The Detroit Lions gambled and seemed to get the 2-point conversion they needed for the win against the Dallas Cowboys on Saturday night. But somehow officials didn't register offensive lineman Taylor Decker reporting as eligible before he caught a pass.

That will lead to a long debate in the never-ending story of NFL officiating mistakes this season.

The Lions' 2-point conversion attempt with 23 seconds left that went for a score to Decker was wiped out due to an illegal touching penalty. The Lions had an extra offensive lineman, Dan Skipper, come in the game before the play, and three Lions linemen, including Decker, moved toward referee Brad Allen and seemed to say something, ESPN's replays showed. Decker was not announced as an eligible receiver, which meant he wasn't allowed to catch the go-ahead 2-point play. The score was taken off the board as Lions head coach Dan Campbell screamed at officials. That score would have put the Lions ahead 21-20 with just a few seconds left.

The Lions had two shots at the 2-point conversion after that, due to a Cowboys offsides penalty on the first attempt, but Goff threw incomplete on the last attempt and the Cowboys hung on to win 20-19.

Campbell made an aggressive call after the Lions scored a late touchdown and it seemed to work. But for some reason, Decker wasn't announced as eligible.

"All I really want to say on it, so I didn't get myself in trouble, is I did exactly what coach told me to do," Decker said, via Nolan Bianchi of Detroit News. "Went to the ref, said 'Report,' yeah. It was my understanding too that Dan brings up the possibility of those plays pregame. I did what I was told to do, did how we did it in practice all week."

Another officiating controversy for NFL

The replay showed that the Lions' linemen seemingly made an attempt to correctly report.

The Lions had clearly prepared for that 2-point play. ESPN's Troy Aikman said about Decker not reporting, "I'm not so sure it didn't happen." Another ESPN replay showed Lions quarterback Jared Goff motioning to Decker to talk to the official, and Decker moved that way.

"Taylor Decker also walks over the official and you only do that if you're telling the official you're reporting as and eligible," Aikman said. "I don't know if he just didn't hear that or what. They said that only Dan Skipper reported, but the evidence is on the tape.

"Initially I thought, well, he didn't report because he's in the game. It's hard to believe that he didn't."

ESPN officiating analyst John Parry seemed to agree that Decker made an attempt, but for some reason it wasn't recognized.

"I don't think [referee] Brad Allen ever recognized Decker," said Parry, who was an NFL official for 19 seasons. "I think he sees No. 70 [Skipper] come off the bench and he follows him all the way into the line of scrimmage.

"I think Decker tries to get to him and say, 'Hey, me too, I'm with the eligibles on this play.'"

Aikman pointed out that Decker was trying to tell the official without drawing a lot of attention to himself. The Lions didn't want to alert the Cowboys that Decker might have been running a route.

Campbell was clearly upset with what happened.

Dan Campbell said he explained play

Campbell was asked what explanation he got from the officials afterward.

"70 reported," Campbell said, referring to Skipper's uniform number. "The explanation was '70 reported.'"

Reporters continued to ask Campbell about the play.

"Two people can't report," Campbell said. "I don't want to talk about it."

Then, without another question being asked, Campbell indicated he told officials about the potential play before the game. It's not uncommon for coaches to alert officials to potential gadget or trick plays that might be run during the game to avoid a penalty.

"I explained everything pregame to a T. I did that," Campbell said. "70 reported, 68 didn't, we threw it to 68. That was the explanation."

ESPN brought Parry back on after Campbell's explanation and he said two players can report as eligible on the same play.

"Uh, no," Parry said. "Two eligible or ineligibles can report to play the opposite position that they need to. Two is not the issue. The issue here tonight is did Brad Allen hear, did Brad Allen recognize visually or verbally with No. 68? I don't think he does.

"I'm guessing Brad Allen, based on his mannerisms, his eyes, where his hat is looking, he never recognized him."

Parry said it seemed the referee Allen never recognized Decker, and that was the player's responsibility to make sure it happened.

"Absolutely, it is on the player," Parry said "It's a unique play, it's a gadget play. You want to make sure the referee definitely knows what position you're playing."

Campbell was still fuming late in his media conference when was asked about being frustrated.

"Would you be frustrated right now?" Campbell said, answering a question from Detroit Free Press beat writer Dave Birkett. "I don't like losing, Dave. That's what happened. We lost. That bothers me. It bothers me. I don't like having an L. That's the frustration. I'm sorry, I don't mean it at you."

Then Campbell abruptly ended his media conference and walked off.

Referee Brad Allen explains controversial play

After controversial calls, officials meet with a pool reporter after the game. Allen spoke to Calvin Watkins of the Dallas Morning News, and Allen said Decker did not report.

Allen said that Skipper did report and then lined up at a normal offensive tackle position, so he didn't need to report.

“So, actually, he didn’t have to report at all,” Allen said. “No. 68, who ended up going downfield and touching the pass, did not report. Therefore, he is an ineligible touching a pass that goes beyond the line, which makes it a foul. So, the issue is, No. 70 did report, No. 68 did not.”

Allen was asked about Decker seeming to go up to him and report as eligible, and then Allen having a conversation with the Cowboys’ defense, but Allen didn’t acknowledge that Decker seemed to report to him.

"That conversation is where No. 70 reports to me, and I then go to the defensive team and I say to them, ‘No. 70 has reported as an eligible receiver,’ so they will be aware of who has reported and then I return to my position," Allen said, via the pool report. "That was the conversation with the defensive line."

Allen also said that since Skipper did report as eligible and then he was covered on the line of scrimmage, that would have been an illegal formation penalty. But the penalty on Decker's illegal touching was the one that was accepted.

CeeDee Lamb hits huge 1st half play

Before the officiating controversy, the first half featured plenty of mistakes from both teams. Even on the one big highlight of the first half, Cowboys receiver CeeDee Lamb scoring a 92-yard touchdown, the Lions whiffed on sacking QB Dak Prescott for a safety when a blitz was unblocked. Prescott deftly moved out of the way, kept the play alive and hit Lamb downfield for the longest play from scrimmage of the NFL season.

Lamb had a massive game, with 13 catches for 227 yards. He also set Cowboys single-season records for receptions and receiving yards in the game.

There were other big errors in the first half. Lamb fumbled right before crossing the goal line, and it went out of the end zone, giving the Lions possession. The Lions hit a nice fake punt after that but went for it on fourth-and-goal from Dallas' 4-yard line and threw incomplete.

The Lions' defense played pretty well but the offense didn't score a touchdown in the first half. The Cowboys led 7-3 at halftime but couldn't feel too good about the way they played. Other than one enormous play, it was a troubling half for a team that was coming in on a two-game losing streak.

Cowboys take a 4th quarter lead

The Cowboys' defense started giving up plenty of yards, particularly on the ground. David Montgomery scored on a 3-yard run to give Detroit a 10-7 lead early in the third quarter.

It took a long time for the Cowboys to take back the lead. Finally, with 7:20 left in the game, Prescott hit Brandin Cooks for a touchdown and Dallas led 17-13.

The Lions went three-and-out and punted, and the Cowboys had a shot to put the game away. But Aidan Hutchinson had a huge sack on third down with 2:40 left and it gave the Lions another shot at the win. But safety Donovan Wilson picked off Goff just ahead of the 2-minute warning. Detroit had yet another shot after that. The Lions got a stop and the Cowboys kicked a field goal for a 20-13 lead, but there was more than a minute to go. Goff hit rookie tight end Sam LaPorta on back-to-back plays to get into Dallas territory.

The Lions kept marching and Amon-Ra St. Brown scored on a catch from Goff with 23 seconds left. It seemed obvious that Campbell, who is very aggressive on fourth downs, would go for 2 and the win. He said after the game that his plan before the drive started was to score and go for 2. The Lions went for it, then came the play that led to the officiating controversy.

"Pretty confused," Goff said. "What I do know — I don't know if I'll get fined for this — I do know Decker reported, I know Dan Skipper did not. I do know they said Dan Skipper did. It's unfortunate."

Goff said later: "I don't think it was, there was no 'the fix is in.' It's not that. They just messed it up. It happens. It's part of the game. But unfortunately it happened on that play."

The Cowboys escaped. The debate will rage about what happened on what would have been the game-winning conversion.

"It sucks. It's unfortunate, man," Goff said. "I don't know if I've had this feeling before, where you feel like you've won but you didn't."