Your friend doesn't sound like a fun gi.
Now, I'm not a mushroom expert by any definition but I'd be extremely careful with all of this. I would not trust that 'friend' to identify mushrooms again. People make mistakes. But it's more that he presented himself as an absolute guide, he was responsible for you, and it wasn't just one species, it was two to three (although one is bad enough!).
Personally I think this is something you should do only if you really know what you're doing - i.e. you've studied it, grown up with it or taken some sort of extensive course where you garner expertise.
Would I ever eat any mushrooms, gathered from the wild? Well, yes.