Much too far fetched to be credible
charcoal gas masks used as underwater breathing apparatus?
a fully equipped drugs factory inside a prison?
managing to punch a guy just right so you knock out his diamond tooth (diamond which looks to be several carats in weight!) and then attaching it to a pipe firmly enough to make a tool to cut through a metal plate?
having a prison ventilation system conveniently leading into a disused tube station?
come on...?!
absurd!
Not to mention every cliché in the book - getting your foot trapped in the train tracks as the train is approaching. Please!
Pity, because the performances are terrific.