ALL drugs that effect the mind will act differently on different people especially psychedelics all of those reactions are somewhat "normal" on some level though
your buddy just went into a bad trip, it can be pretty common, and you shouldn't be reluctant, just go in with a good mind set and nothing to worry about and go with the flow and you should be fine, the person greaty affects the mushroom trip, or any psychedelic trip for that matter, if your an unstable person emotionally and mentally i would reccomend stopping the use of psychedelics immediatly....