Oof, that's brutal. Sounds like you bought the "viral" promise instead of an actual tool. Been there, got the useless t-shirt.

Did the customer admit they moved it for painting, or did they play dumb? Always makes me wonder.

Flew just fine for years" is a TERRIFYING way to look at it. That hidden rot is a total gamble. It might hold, or it could fail on the next hard landing or bit of rough air. Finding it means you caught a major safety problem BEFORE it turned into a disaster. Calling that "fine" is how people get hurt.

Feel your pain, that's so frustrating.

That cake sounds wild, what recipe did you use for it?