Massive oil leaks.

Well, it's entirely possible someone other than the master put it together. Hired help can really hurt a reputation. But it's also possible this was just a series of "whoops" - we're all human. At that point it goes back to how does the shop handle the issues assuming the owner allows them to.

Good point. I had an engine builder in my area who was very good. He did lots of motors of all brands and types that all were sucessful. All of a sudden, myself and other guys had problems with his work. We found out that he was trying to teach his mentally handicapped son to do the work. He retired soon after the poop hit the fan. We are all Human, and stuff happens.