Death Messages shows "whilst fighting [mob]" at the end even when mob is killed

I was fighting a mob in survival but then i killed myself with Flint and Steel

What it would show:

FunAndJokes555 walked into fire

What showed instead:

FunAndJokes555 walked into fire whilst fighting Spider

Seems /kill don't have effect after killing a mob, but in some other death reasons, yes.

Affected both Vanilla and Modded Minecraft.