"ITs interesting though. How could the club let a completely new guy, new to RC, just go ahead and fly the plane without any instruction?"

Again see that I wasn't there on Wed when he first showed up. If I was, I would have seen him and known he was new because I saw him in the local hobby shop asking questions the week before. I specifically directed him to our club website to where he could get in contact with an instructor and told him that he could come out on any Tuesday as that is training night.
We have 3 clubs around here and memembers just jump back an forth all the time. Just because there is someone at the field that you havn't seen before doesn't me he doesn't know how to fly. Heck I don't know more than 5 guys names at my current club because I switched from a different club last year. Generally if we see a new face with a trainer someone will offer a "need any help with that?" If the answer is no, then your on your own. The only reason the club president allowed him to keep flying is that he is an AMA and a club member.