WIll X30 run with cracked block?

I posted a while back about my buddies MC X30. He was told that he didn't have to winterize because he has the Caddie engine with the sealed system. Well the boat was running really rough when the Marina guys moved it and would only move in reverse. He had MC pick it up for service and the dealer said that he had a cracked block and that the oil looked like chocolate milk. Obviously my bro is extremely bummed because he doesn't have the 9K to replace the engine and has written his boat off for the season.

Now here's the thing I need some input from you boat gurus on. I went riding with the dude when he first took it out in March and the thing seemed to run normally. We even did a couple of sets each that day. He left it overnight and when the marina guys tried to move it the next morning was when the problems began. Would a boat with a cracked engine seemingly run for an hour or two and then kick the bucket? Is it possible that he has a lesser problem or can a block sometimes be repaired? I really wish that I could deliver some potentially good news to him. He's bummin' hard.