Draymond Green is one of the smartest players in the NBA. That needs to be mentioned in almost any context surrounding his performance, but is especially notable in the rare moments in which he makes a mistake. Things like this don't happen to Draymond very often, but even the best players are susceptible to the occasional gaffe.
Draymond's came with his Warriors down 103-100 with 8.7 seconds left on the clock. Golden State needed a 3-pointer to tie the game, but Green, either because he thought the Warriors had less time to work with or because, for some unknowable reason, thought he'd been fouled, hoisted up a miracle 3-pointer from near the half-court line as soon as he caught the inbounds pass. He predictably missed, and the Spurs walked away with a 105-100 victory.
Draymond might have expected a foul on the attempt. That would have put him on the line for two free-throws when Golden State needed three. But to bet the entire game on that hope likely wasn't Golden State's plan. The Warriors either could have played out the possession and gotten a better shot, or played the foul game, hoped Green made both of his attempts and San Antonio missed one of theirs and tried again after that. No matter the rationale, the shot was about as poor an outcome as Golden State could have hoped for on the possession.
But Green is human, and even the best players in the NBA make mistakes like this every now and then. Green was on the floor for a famous one, as J.R. Smith forgot the score at the end of Game 1 of the 2018 NBA Finals. Smith's teammate, LeBron James, threw an inbounds pass off of his own backboard the next season. Mistakes are a part of basketball, and a rare one from Green helped San Antonio walk away with a victory tonight.