Someone forgot to tell that guy guarding the bomb who was watching the doorway to the area the bomb was in that there was a second way to it
All you really have to know to understand this play (via MLG) by Call of Duty pro Jared “Nagafen” Harrell is that he’s is the last man standing on his team, and he needs to defuse a bomb to win the round. The other team thinks they’ve got the bomb locked down but was ninja'd in the end.