Yeah! Your bevel gear failure is the first I've seen too!
Like B.D.F., I got to have a look-see at the pulled bevel drive. It looked perfect, and I had one trackday under its belt at that time. Also, I inspected the new unit before it was installed. As a mechanic myself, what specifically liked was that it looks like the drive units clearances are setup by hand. I could see the "setup grease" on the gear teeth faces, and the pattern was perfect.
You must POUND that bike!