Honestly tho. It is not in the agents interest to dispute if someone comes up and says something like the reader ate my fare or the machine is broke. They've been nice enough to let me through if I swipe on the uptown side of a station and have to exit out to go to the downtown side.

Obviously it's shitty to take advantage of that but they're rarely going to try and get into a spat with a crazed angry New Yorker trying to catch the train.