Having watched his other videos, the 520x10 was probably with the safety squat bar, with the hands on the uprights, with a suit and wraps, going down to well above parallel. It is basically a glorified leg press that makes the dude think he is the god of powerlifting coaches.
If the program was working and making the kids incredibly strong then they would be able to display that strength doing the power lifts raw. Watching their raw videos, that is obviously not the case. 135x10 is a very average bench for freshman and sophomores that lift a couple of times a week for a few months.