In the immmortal words of Olivia Newton-John, Have You Never Been Mellow?
Yes, clearly, he was throwing his headband to the equipment manager, who sits on the baseline, not anywhere near the Nuggets bench. And we all know how those headbands can get messed up during the game. You really need the equipment manager to work on them every chance you get. And there's no time to waste, so you have to throw the headband to them.
You're not that stupid? On the contrary, you would seem to at least that stupid.