In the brutal, beautiful theater of professional sports, there is an unwritten contract between the athletes and the audience. We, the fans, agree to invest our time, our passion, and our money. In return, the athletes agree to compete with honor, to let skill be the ultimate arbiter of success. Last week, in a heated contest between the Las Vegas Aces and the Indiana Fever, WNBA superstar Kelsey Plum took that contract, tore it up, and threw it in the face of everyone watching. After being spectacularly beaten on a highlight-reel play, Plum responded not with resilience, but with a blatant, dangerous trip that was less a basketball play and more a toddler’s tantrum on the hardwood. The moment has since gone viral, serving as a perfect, ugly case study in the anatomy of a sore loser.

The sequence began as a moment of pure basketball artistry. The Fever’s crafty guard, Erica Wheeler, had Plum isolated one-on-one. Wheeler, known for her shifty handles, unleashed a devastating left-to-right crossover that sent the two-time champion stumbling, completely crossed up and beaten. It was a clean, decisive victory of skill over defense, the kind of play that makes basketball beautiful. As Wheeler drove past the fallen Plum toward the basket, the highlight was seemingly complete.

But then, the ugly postscript. Plum, sitting on the floor and completely out of the play, made a conscious decision. She extended her left leg directly into Wheeler’s path. The contact was immediate and unambiguous. Wheeler went crashing hard to the floor. It was not an accident. It was not a tangle of legs. It was a trip, a move more at home on a playground than a professional court, and it was a profound betrayal of the spirit of the game.

The referees correctly and swiftly assessed a flagrant 1 foul for unnecessary and excessive contact. But the judgment of the court of public opinion was far more severe. The clip exploded online, and the verdict was nearly unanimous: this was a dirty play, born of pure frustration. Plum had been embarrassed—”cooked,” in the modern parlance—and she lashed out. She couldn’t stop Wheeler with her skill, so she resorted to a dangerous and unsportsmanlike act that could have caused a serious injury.

This incident has ignited a fierce debate about Plum’s character as a player. For her detractors, this was not an isolated incident, but a confirmation of a long-held belief. Plum plays with a fiery, abrasive swagger that often toes the line of sportsmanship. She is, as one commentator aptly described her, like an “annoying gnat at a barbecue,” a player who prides herself on getting under her opponents’ skin. For critics, this trip was not a momentary lapse, but a window into a “win-at-all-costs” mentality that has no problem crossing the line when pride is on the line. The comparisons to notorious NBA tripper Grayson Allen came fast and furious, a label that, once applied, is incredibly difficult to shed.

Of course, a more charitable interpretation exists. Supporters of Plum argue that while the play was reckless and foolish, it may not have been malicious. In the split-second chaos of being beaten so badly, perhaps it was an instinctive, clumsy flail, a desperate attempt to recover or kick the ball that went horribly wrong. They would point to her decorated career—her championships, her Olympic gold medal, her reputation as a relentless worker—as evidence that one regrettable moment should not define her entire legacy.

But this defense, however well-intentioned, misses the point. The reason this play struck such a nerve with the public is that it violates the very essence of sporting competition. We watch to see skill rewarded. Wheeler’s crossover was a moment of supreme skill. Plum’s trip was an attempt to nullify that skill with a cheap, dangerous, and unskilled act. It feels like cheating. It feels like a rejection of the meritocracy that sports are supposed to represent.

In the new, high-visibility era of the WNBA, where millions of new fans are tuning in, every action is magnified. This incident was not just a foul in a basketball game; it was a lesson in sportsmanship broadcast to a national audience. And the lesson it taught was a poor one. It said that if you get beaten, it is acceptable to retaliate in a way that could injure your opponent.

Ultimately, only Kelsey Plum knows her true intent. But in sports, you are judged by your actions, not your intentions. And her action was to trip a player who had just bested her. In the intense pressure cooker of a professional game, character is not revealed when you are celebrating a victory, but in the precise moment you are spectacularly defeated. On that night, Kelsey Plum was defeated by a brilliant basketball move, and in the seconds that followed, she failed the test of character that came with it. The stain from that ugly, unnecessary trip may prove far more lasting than the temporary sting of any crossover.