Major failures like that are pretty rare and I have never seen any data correlating them to engine management, parts history, etc.
From what I've read, unreported shock loading has been suspected as the cause of cracks in a crankcase; it's hard to see where crankcase cracks could come from otherwise.
Did Timothy's engine throw a piston? It looks like a cylinder came out, which would involve a number of bolts snapping (or their studs/nuts coming undone).