There was a play set, the problem was execution. They were having problems inbounding the ball and to avoid getting the inbound call, the pass was made to an unexpected Bosh
who was toying around at the 3 point line at the time. But when he gets the ball he tries to resume the play.
If he was smart, he would have analyized the situation, saw that the setup play wasn't going to work because he wasn't even near 10-18ft from the rim. He should have passed the ball to a shooter given the fact that that Portland was playing zone, but instead he went up for a heavily contested layup that had absolutely no intention of getting in. He just threw it at the backboard prayed to god that he'd get a call.