I don't know the funniest way to phrase this, so I'll simply ask. Have you MET him??? I'm still impressed though. I don't think I could get that drunk if I tried.
Your 4NT-Blackwood agreement is the issue IMO. It doesn't make a whole lot of sense to play this before either player has gotten a chance to describe his distribution.
wtf 4♥? Looks like an auto 4♠ to me. South already bid hearts 3 times and has spade support. I agree with 3♥ though. 5♣ is obviously a slam try of some sort. I'd guess that partner has either 5260 or 5170/5161 with the ♥A. If I could bid 4♠ to play now I would. I guess since partner thinks we're playing in hearts I'd better sign off in 5♥. The right dummy may produce a decent slam (AKxxx A Axxxxxx --- for instance) but I really just want a plus on this one.