The first time I sent my speedmaster for repair (an issue with the crystal at first, then upgraded to an issue with the stop-watch's second-hand not stopping at 12-o'clock AFTER the watch was checked by them) was at the Swatch group at Wheelock Place (Omega's service center in Singapore).
The watch was with them for a week and upon receiving it back, found that the white-paint at both edges of the second-hand had been scrapped off , as if someone had used a tweezer to pinch it too tightly while removing the second-hand and scrapped off some paint in the process!
Although my issues with the watch was resolved, it was unfortunate that such a thing happened during the repairs.
It was a pity I did not detect this on the spot but only upon reaching home. I hope someone from Swatch group or Omega is reading this and send their technical service staff in Singapore for training in the handling of such delicate instruments once again.