I was in a soul sand valley with a full set of Thorns armour and noticed that sometimes when a mob dies due to your Thorns, it can make them play their damage sound instead of their death sound. This seems to becaused by the game calculating the damage individually between each piece of Thorns enchanted armour and sometimes it applies a weaker damage and then a stronger bit of damage, which is enough to kill the mob in the same tick, however, it only calculates the damage noise even though it should play the death noise since the mob dies in that tick.

Steps to reproduce

1. Wear a full set of Thorns enchanted armour, and optionally put a Thorns item in each of your hands as well.
2. Spawn in a hostile mob. Ghasts are a good example of this because their death noise is very distinct from their hurt noise
3. It is Suspected that if you do this you will be more likely to be able to reproduce this: (Deal enough damage to take that mob to 2 HP or 1 heart.)
4. Let the mob damage you
5. Repeat until successful reproduction. The mob will rarely make the hurt noise upon its death.

Observed result

The mob plays their hurt noise occasionally when dying to thorns armour rather than their death noise

Expected result

The mob to always play their death noise upon their death