You Can Crack a Safe with Liquid Nitrogen

Plot:

In the final episode of the series, Penn & Teller present their last seven unbelievable stories, where all are true except one which is false and the viewer must decide. The stories presented: Did ancient Greeks really create arrow-proof armor using multi-layered fabric? Can you really crack a safe by dipping it in liquid nitrogen? Can you pour a drink in reverse in a plane when rolling? Is there really a blind man whom can mountain bike using echo location clicking? Can powerful MRI magnets be used to removed tattoos? Is there a city that uses modified speed bumps to create music when you drive over them? Can a snail crawl across a razor-sharp blade unharmed?