Wow! The villagers are out with their torches... No one has seen the job in question, or knows what the true, chemical condition of the 25 year old paint was,or what the agreement was. In all my years of painting I've seen some pretty crazy things, like cheap shops not adding hardener to enamels & throwing it in a bake booth, etc. etc. There are a lot of unknowns in refinishing previous jobs. If I bid that job, I would give him one price to refinish with no guarantee & another price to strip, address any issues, prime & paint with a guarantee and let him make the decision. Sealers are only an insurance policy, not a cure all. As a side note, I always feel better about stripping off old finish, because I only like to do it once and there are No unknowns. Communication is really important. People can be reluctant to tell the painter what their expectations are for fear of high prices. I'm probably not making any friends, but it seems to be the biggest problem with "Evil Painters" and car enthusiasts.