I have had several occurrences where I have been killed by a mob (hearts depleted) but also knocked off the edge by his death blow and had two lives deducted as a result. I would think once I am already dead, I would not be able to die from the fall too.
I also had a case where in world 1 I was knocked/fell into poison just as the loading screen came up to move onto a new area and could hear my health ticking down while it loaded until I died. Shouldn’t the loading screen stop all action and prevent this kind of thing?