Zaza Pachulia took one step. One shuffle, one slide, one stab of his left foot. And then he took another, and changed the course of Game 1 between the Warriors and Spurs, of the Western Conference finals, and of the 2017 NBA playoffs as a whole.

Pachulia’s slide and his injurious contact with Kawhi Leonard’s landing left foot were the most important moment of Golden State’s 113-111 victory, and probably the most important moment of the series and the playoffs so far. The Spurs were well on their way to a win that would have challenged NBA destiny and disrupted the preordained plan for a Warriors-Cavs re-rematch. Kawhi’s injury sucked the life out of what was suddenly a wonderfully compelling series, and likely robbed us of pre-NBA finals drama that we assumed we weren’t going to get. Leonard doubtful for Game 2, and likely won’t play a competitive basketball game with a 100 percent healthy left ankle until October.

All of that is why the play was and is such a big deal, and why it has been the most-discussed aspect of Game 1 ever since it happened. But why has the debate over the play, revolving around the issue of whether Zaza’s slide was intentional, become so heated?

The answer to that question dates all the way back to July.

Pachulia may or may not have known exactly what he was doing. He may or may not be a dirty player. The dangerous move may or may not have been intentional. But one thing is certain: Fans of the NBA want it to have been intentional. They need it to have been intentional. Because they need a villain.

And ever since July 4, ever since Kevin Durant joined forces with a 73-win team, the Warriors have been the villains.

Or at least we’ve wanted to cast them as the villains. But the reasons for shoehorning them into the role were always somewhat shaky. Who were we to denigrate Durant for making a move, that, however lame, was in his own best interest? Who were we to vilify a team whose best player, Steph Curry, is as likable and as innocent as superstars come? And whose coach, Steve Kerr, has been so bright and warm despite agonizing private suffering? We were angry at the Warriors for making November through May significantly less interesting, but did that merit hate?

No, it didn’t, and doesn’t. Sports hate is often somewhat irrational, but Warriors hate was particularly irrational. We all felt it and understood it, but there’s a difference between understandable and logical. Logic would suggest anger at the league’s structure, what it allows and what it incentivizes, or it might suggest undirected frustration. Emotion, though, suggested anger at the Warriors.

Thus began the vilification. The narrative was established within weeks of Durant’s move, and fans have been searching for narrative fodder ever since. Human beings like to convince themselves that backwards logic is better than illogic, and that’s exactly what non-Warrior fans did. Without concrete reasons to detest the Dubs, they took up the position and then sought out the concrete reasons. This is why, for example, Draymond Green’s transgressions and flamboyance have often overshadowed his brilliance.

Whatever the reasons for Warriors hate, it has caused confirmation bias — the tendency to interpret evidence as confirmation of preexisting beliefs — to run rampant. And there is no better evidence of its presence than the reaction to the Zaza play. The preexisting belief or opinion is that the Warriors are villains. The disputable evidence is the play, and everything you’ve seen and heard in the 24 hours since. The interpretation is that the second step was intentional or dirty, because that would support the stance that the Warriors are in fact villains.

There is no way to know whether that interpretation is correct. On one hand, Pachulia’s head is turned in the other direction, and he appears to be agitated or surprised by the referee’s whistle. On the other, the extra half-step seems unnecessary, and if there’s anybody in the NBA who would expertly feign surprise in this situation, it’s Zaza.

On one hand, Zaza’s reputation, along with the stakes, the outcome of the play and the magnifying glass that is instant replay, could be causing us to overreact. On the other, Pachulia’s history is extensive; he flagrantly fouled Russell Westbrook earlier this season, almost broke Leonard’s arm last year, and swung his elbows in a dangerous manner on multiple occasions against the Spurs as a member of the Dallas Mavericks.

On one hand, Leonard himself didn’t think the play was intentional. On the other, a fuming Gregg Popovich called it “not appropriate, dangerous, unsportsmanlike.”

On one hand, just about anything Popovich says should basically be treated as gospel. On the other, maybe not when it comes to stepping under jump shooters, because Pop was on the opposite side of the debate when it was his player doing the stepping.

In the aftermath, many have pointed out that, regardless of intent, the play was illegal, reckless and avoidable. It needs to be stamped out of basketball. But the legality of the play, in a weird way, is tangential to the fierce debate. An illegal play doesn’t justify hate; a dirty play, in the minds of some, can. That’s why the play has become so divisive. It has, roughly, split fans based on their natural inclination to vilify the Warriors, or their natural inclination to defend them.

There are, of course, other reasons for the ferocity of the debate and the attention paid to Pachulia’s actions rather than the injury itself and the ramifications. Chief among them is the insatiable human appetite for explanations or blame beyond chance or randomness. But this debate has become particularly passionate because it may be the exact confirmation of villain status that so many NBA fans have craved for months.

More from Yahoo Sports:
• Michael Lee: Why Popovich was so angry about Pachulia incident
• Unlikely hero sends Celtics to conference finals
• Latest arrest likely to end troubled NFL star’s career
• Adrian Wojnarowski: Magic want to talk to Cavs GM