There were a bunch of watches initially, cut down to 3 after preliminary testing: An Omega 321 Speedmaster, a Rolex Valjoux 72 (pre-Daytona), and a Longines 13 ZN (which surprises me that it wasn't a 30CH).
The Daytona hands didn't "melt"; the sweep seconds hand warped during the pressure test and caught on another hand stopping the watch. The watch also stopped running during the humidity test (maybe because of the same issue). The crystal kept popping off the Longines.
The Speedmaster had a fault or two also, but it was the only watch that kept working. For example, it gained 21 minutes during the decompression test and lost 15 minutes during the acceleration test, and there was a problem with lume failure also. On Apollo 15, the crystal of David Scott's watch came off during an EVA so he used his personal watch for the next EVA.