"A diagnostic clue of extreme poisoning by H2S is the discolouration of copper coins in the pockets of the victim"
I've worked around high power free-space infrared lasers where a single stray reflection could instantly blind you permanently (and you can't see infrared light scattering off of stuff like you can with visible lasers). I'd rather spend years working with those than spend one afternoon in a lab with a sample of H2S at 140 GPa. I don't care if it's inside a diamond anvil cell inside a cryostat. High pressure H2S has got to be a freakin' nightmare to work with. I'm sure H2S has lots of funky properties nobody knows about because practically nobody wants to work with the stuff. Kudos to the PI who convinced a bunch of grad student peons to put their lives on the line... I suppose.
They probably have absolutely tiny quantities of the stuff under pressure. Not enough to hurt anyone even if it escaped.
I don't know if this is still the case in this litigation-happy age (probably not), but when I was in high school it was a common beginner's chem class experiment to make small quantities of H2S.
My physics teacher once commented that he hated it when they did that, because he'd smell it for a while, then not smell it any more -- leaving him to wonder whether it'd just gone away, or whether people were going to start keeling over.