I hear ya, you wouldn't belive some of the issues I have seen, mainly from dumb mistakes.
I try to always have back ups, just incase.
had a guy stick a ztr in the mud, so he gets his coworker to get the other z and pull him out, well Guess what, he stuck this one too, so I had 2 z's stuck badly, it took me around 2 hrs to get em out, of corse 2 hrs for me and them that = 6 man hrs. there goes a day...
Best of luck
Dont even talk to people who cant purchase your product or service.........Dave Thomas.