[JBotAlan]

I would love to cite a rule, but I can't seem to find one.

The way I understand it: popping a game piece is field damage, and so it is the judges' call--if they think your 'bot poses a threat of popping game pieces, they will make you fix it. If they see you pop a ridiculous amount of game pieces on the field, they'll probably shut you down. But they expect there to be a lot of deflated tubes, and they probably won't penalize you at all if you accidentally drive over one and it pops. Just don't do anything foolish, and you will be fine.

You might consider submitting to the QnA if nobody else posts a definite answer.

JBot

EDIT: Well, a lot of people beat me. Oh well.