Sounds like you've not been around someone who is having a bad trip, it's traumatic. I've been around some and had to play caretaker till they came down.
A bad trip on MDMA? I've never heard anyone express that they had anything like the classic LSD "bad trip" on MDMA. It's just not especially psychedelic in that way, and broadly speaking, it's a stimulant that makes your body feel really intensely good.