Caliber561
·I saw this in another forum a while back (not as wonderful as this forum of course) and it seemed to cross reference with the design... but correlation is not causation as they say.....External pressure was meant to compress the gaskets and provide a watertight seal that increased with depth. Regardless of whether that bit actually worked or not, the design left the watch poorly sealed when there was no external pressure
However, you are making the assumption that the crowns provided inadequate protection in shallow depths. It has been stated that it is more likely that these crowns gained an unreliable reputation as they were not screw-down and were not often replaced when expired. Had the crowns been screw-down, unintentional manipulation would be avoided, though failure to replace the crown upon gasket failure would compromise the watch anyway.