[Is this a bug?] I die because 'minor damage'

[The Grim Sleeper]

cardiac failure. (...) can still persist like a time bomb

This seems plausible. I had been in crit and saw the "Your heart lurches in your chest"-warning, before getting patched up, but no warnings after I stopped being unconscious.

Also if you have no legs you can use the P hotkey to pick stuff up on the ground and quickly use it on yourself.

So if the 'emergency epinephrine injector' had dropped to the floor, I could've picked it up and used it, but could I have opened the medkit in a prone state and taken the injector out?