I shall disagree. Perhaps I identify more with Mr. Helmet than I care to admit. Except I just admitted it. So maybe not.
Was he repentant? Willing to learn? Did he blush with shame when he saw you again?
I'm weirdly academic and dilitantish (that doesn't look like its spelled correctly. Help me out BD.), so when I bought my bike I also bought about 6 biking books and committed them all to memory. They probably bailed me out of some bad scrapes.
Still, when I showed up to group rides I felt like a fish out of water and on a bike that he didn't really need. As observant as I've been, I still make noob mistakes on group rides. Perhaps I've been written up on the Young Turk forum and just haven't realized it.
So I would have given him another chance. And recommended a copy of "Cycling for the Complete Idiot". As nicely as I could.