If I drink a potion of harming (instant damage), and it finishes me off, the glass bottle of the potion that killed me vanishes.
Reproduction steps provided by Amo_ here
MC-230553 Empty bottles won't drop if player dies to harming potion
MC-257498 Drinking potion of harm to die lose one bottle
MC-264062 The potion does not drop if you kíll yourself using potions