Press RT to fire machine gun

Games Halo: The Master Chief Collection
1

In the End of Halo 4’s mission midnight, you’re meant to get a prompt to use a grenade.
However, for some reason the message keeps showing up as ‘Press RT to fire machine gun’.
Pressing the right trigger still does use a grenade like it’s meant to.

2

I think this has been an issue since launch. It’s quite funny, but still no word if they plan to fix it.