Yeah, DeRozan inbounding the ball was strange. Few things to consider:
1) The play was an alleyoop to Gay. Gay was to set a pick and then DeRozan lobs it hoping for the Grizzlies to switch and be slow to rotate.
2) Gasol played so far off Aldridge that Aldridge audibled and popped out. Not a terrible decision by Aldridge -- but Gasol recovered quickly. At that point, DeRozan's only available pass was to Aldridge.
3) With the play being an alleyoop for Gay, the logic for DeRozan inbounding is the Spurs needed three-point shooters on the court for spacing. Plus, with the son of the legendary Jaren Jackson defending the inbounder with his 7-foot-10 arms, the inbounder had to be someone with size. I can see what the coaches were thinking. You can have Belinelli or Bertans inbound the ball . . . or you can just put spacers on the court and have your best passer in DeRozan inbound the ball.
Guess that's what happens when your best scorer, most clutch player, best passer and best passer with size is all the same person. Still, though, if I'm drawing up the play, I'm giving to DeRozan for a jumper, tbqhwy.