Did Roy hustle the Whammer?
The throw that missed the cans, prompting Whammer and Max to laugh at him, was so weak and completely off target compared to later throws that struck Whammer out and hurt Sam's hands when he caught them. Plus it's a classic hustling move, appearing to suck at whatever the game is to draw your bait in. On top of that, Sam is awfully eager to bet that money. No hesitation whatsoever.
On the other hand, Roy tells Sam he wished he hadn't bet money. So which is it? I honestly can't make up my mind,