i would seriously take it to a mechanic, or a toyota dealer and have them find out what miles he was going when he shifted to 2nd.
u can go higher than 60 on 2nd, but think of it this way. driving on 5th gear doing 60 maybe ur around 4k rpm, and then all of the sudden you downshift to 2nd without revmatching, first of all, the car is gonna jerk like crazy, ull damage the motor mounts well enough, and then ull put the engine in one big of a fuckin stress. that could cause a problem.
i dunno man, you dont want someone to fuck up ur car before you owning it, and then he tells you "its fine", his mechanic says the same cz ur friend convinced him to say so, and 2 months down the road ur car goes nuts on u.
plus i say ur friend is a pretty bad driver, how would you shift from 5th to 2nd? one is like 2 miles from the other.