What is the biggest plothole you have come across?

Not the biggest, but one that always bothered me is in the movie “the rock”. When they are entering Alcatraz from beneath, there’s a metallic door and some sort of furnace spewing flames. Sean Connery says that he memorized the sequence to escape, jumps in the furnace, rolling through as he avoids the fire to open the door from inside to let the swat team in. Now.. why would he go through that trouble in the first place when he was escaping the prison if the door opened from the inside?