I absolutely believe he encountered an hole who was deliberately trying to intimidate people just because he can (and backed off when a taller person and supervisors showed up) but the homophobia element is slightly questionable. At least openly. It's entirely possible the bloke thought he could pick on Adam because he read him as gay. The phrasing was probably added by Adam so he has a sob story and a reason for his book existing outside of retconning his own loveless teenage years and ripping off his audience.