Let's discuss all the ways this final Wemby turnover went wrong.
1) You can see the three Spurs (Vassell, Harper, Castle) identify there's going to be no timeout and run their fastbreak lanes. It's a pretty standard practice of spacing the floor properly with the primary ball-handler De'Aaron Fox on the floor, who is just off the screen to the left. While Castle does look back in this exact moment, if you run the video....he turns his head forward immediately after this frame. As he should! Busting his ass down the floor, ahead of the action, to get to his assigned spot that is discussed lord knows how many times in the film room. That pass should never ever happen to someone running the sideline, and Wemby alluded to this in his postgame press conference comments.
2) Let's just say Castle somehow catches the pass. He is full steam ahead downhill, with no idea what is in front of him because he's looking backwards. Waiting for him is the NBA leader in charges taken. He was set up perfectly to take yet another right here.
3) Wemby chasing after the incomplete pass to make up for his error and barreling into Jalen Brunson, who would have fallen over if a fart hit him let alone a 7'5" guy. The moment was chaotic, and these guys are tasked with making split-second decisions, but to see him double-down and put Brunson at the line was a self-inflicted wound that they make 30-for-30s for. The turnover may have given the Knicks the ball back, but there was no guarantee it would have resulted in points ... and you head to overtime. Now you might have to hear that piano with a guy softly narrating "What if I told you...Area 51 has no secrets?"