This didn't make sense
I agree there are a few things in the movie that didn't add up but one that stands out is at the end when Ryder says he is giving Garber 7 minutes to come down with the sacks of money or he starts shooting passengers.
7 minutes? He has a casual chat on the phone with his wife, this, AFTER he has to make it to the top of a tall building and then get into a helicopter that flies him to Ryder's location before he then has to get off and walk to the bottom of the subway and locate Ryder to give him the cash? In 7 minutes? No, in fact less than that because he "checks" at 6:55.
Annoying.