The burden of proof that the sensors cannot provide false positives falls on the hotel chain, not the person getting charged. There is also the question of whether the sensors can be triggered by someone else, or an adjacent room.

You fight them by filing a lawsuit for fraudulently charging you.

This seems like a good point. That said, the bank is the failure point here. I don't know if they are actually bound to any laws, or if it's just the bank policy?

If I were them, I'd bitch the bank out and threaten to leave. This is such a clear case of fraud they aren't fighting.