I thought you got a new bike, the 750? I really want to check one of those out. If this Ducati doesn't work out (or maybe even if it does), I might want to get one of those or even a Triumph 675.
Is this what happened to your bike?:
That's the steel insert that goes into the case, then the main bearing goes into that. This is the flywheel side bearing, and that steel insert broke right at the oil passage. The main bearing walked outward, and then we have major knocking like you heard at Firebird.
What I found out was, the crank was likely preloaded to .011", and this is Ducati's new spec (actually .012", or .3mm). I've heard of other engines popping like this as well, maybe yours was one of them. Although, you're putting out lots of power, it might just do it anyway... But still, it shouldn't happen. That ring shouldn't break. The old spec was .006", and my dad did the math on it and at operating temperature, the case expands more than the crank and you should end up with just about 000 or maybe .0005 play or so, if everything works out right.
I'm sure you and Art could rebuild it, but it's kind of a PITA. I know first hand... I probably know more about Ducati bottom ends than I really wanted to by now.