man, as someone who trips occasionally i would either have to have a big conversation with a friend like that afterwards, or cut contact entirely if it was just some casual acquaintance. i hope it's just a result of ignorance of how psychedelics work, instead of outright malice, but your mood on acid is heavily influenced by your set and setting (state of mind and environment), and horror media is certainly not something that nurtures good vibes. if someone was prone to indulging negative emotions, this could send them down a bad trip lane, and those can range from a whack afternoon feeling down, through psychological scarring, all the way down to triggering psychosis
be kind to your tripping friends, you can try to freak them out when they're sober if that's the dynamic in your friendship, but don't do it when they're under the influence of drugs that majorly fuck with the mind