Wempe messed up attempting a "quick fix", voided the warranty for tampering with the watch while being a third party, tried to brush it under the rug and have the owner foot the repair bill. Then, upon being comfronted with a photo, they could no longer deny wrongdoing and were left with no other choice but own up to their cockup and take care of the repair cost.
Officially, they didn't openly admit it was their fault, alleged their watchmaker left the company, alleged they lost the photos they took upon receipt of the watch, essentially making any excuse not to be made responsible. They didn't apologise to the owner either.
I would quit any relationship with this AD, personally. It's not about making a mistake, we all make them, it's about trying to hide it and have the owner pay for the repair after voiding the warranty. How could I trust them after this?