Dssd problem.

[CAPDSSD]

The gas escape valve is to let helium (entering the watch while in a high pressure decompression chamber) to escape as the pressure in the decompression chamber is reduced - to avoid Helium pressure exploding the watch from the inside.

If there is little helium entering the watch, then the pressure within the watch would remain closer to atmospheric. In the high pressure decompression chamber, the pressure would tend to push the crown in.