I am amazed that you were confronted for using the restroom. Were the agents uniformed screeners, or suited managers? I never knew that TSA had the authority to interrogate individuals or even hamper the movement of passenger outside the screening locations. If you were to have been questioned, it should have been by law enforcement not by TSA. From your post, Agent #2 was a complete prick. I think that he had something against you. Your pass from the first leg of your flight should have been sufficient and they should have just backed off. It makes me wonder if I'll have to undergo questioning if my stomach decides to act up on me and keeps me on the toilet for an hour. I also wonder if the TSA agents acted on their own or were instructed to confront you. Agent #2 most likely acted on his own and Agent #1 may have been instructed.