Still using Zaino?
Document of Understanding is OK and I'll make an effort based on the results. I'll put in writing all that he claims he has done and incorporate the repair order along with an overview of the problem and the supposed solution. Good Point.
Problem is getting him to sign it.
Another thought would be to recap the problem and send him a letter along with a specific outline of what he supposedly did.
This puts the job in writing and gives me a small small ground of space to stand on!