No lost a few more than that CrabbyJo, but a few were due to PPS. (knocking on wood for this next statement) our last passing was 6 + years ago. A couple were lost due to blunders unfortunately. Lack of knowledge about the difference in E's and PP's our first year of crabbing and lack of ocean water. Shell shock passed in 9 months.

One due to being overheated why I am so persistant about checking substrate temps and have temp controllers on all tanks and iso's here.

And I had a post molter pass, we had a water leak under our slab home and they jack hammered for 2 days.

I assume it was just too much for a post molter who should of had quiet during his recovery.. well at least our 'normal' home noises which did not include a jack hammer being used indoors.
My way of telling, it is hard and I am leery when trying to determine if one passed. Smell, yes is sort of a way, but I always place water within the shell and do not blink to see if there is any type of a twitch. If not then place water within the shell and have it mainly upside down... really more of a slant to hold the water in. This way if the hermie is that weak they can still usually flip their shell down. If the shell moves.... there is life. This can only usually be determined in a iso type area. Also, the underside of the abdomen of a passed hermie is almost a smokey black where normally it is not.