Fireworks Crossbow Multi-shot bug

I was in water, fighting a pillager band (in survival mode), with a loaded multi shot crossbow in my off hand, and a firework in my hand. When I fired my firework, it shot off three fireworks as well as three arrows.

What I expected to happen was...:

**One firework should have gone off.

What actually happened was...:

Three fireworks and three arrows were shot off.

Steps to Reproduce:
I have tried to reproduce it, but have not gotten it to work again. I am fairly sure this will not happen outside of water, because the crossbow will trigger and not the fireworks.

NOTE:

It IS possible that I mistook the arrows for fireworks, but at the moment, it looked like three fireworks and three arrows.