Accidentally
Adam waited until everybody else got off the bus to do it.
The problem was, Matt had been given the world's most annoying Bouncing, Talking Tigger as a fan gift, and as funny as it was to hear the thing bounce around and talk about how that was what he did best, Adam wasn't impressed. And the fact that this thing had become an inside joke among the guys on the bus was too much.
Adam had been awakened several times the previous night because someone had put Tigger in the bunk with him and flipped the switch to make him bounce and talk until Adam wanted to take its head off.
His plan was simple. Figure out the most effective way to silence Tigger permanently and apologize to Matt, claiming an accident. The only problem was, Walter was still on the bus. Adam didn't think he ever left it.
But he was determined, so heedless of Walter's presence, Adam set to work. He took the batteries out first. The thing couldn't function without them. And when he couldn't figure out a torturous enough scenario, Adam simply took Tigger off the bus under his jacket, walked around to the back tire of the bus, away from view and set him down to be run over. It could be an accident. If they chose to look at it that way.
And, best of all, Adam would get some rest tonight.
Adam walked inside the venue, feeling a wicked little thrill as the bus drove off to park somewhere else, and Tigger was officially someone else's problem.