Ah, I remember the end being cut rather abruptly. But hey, there's worse : after the end credits, there's a short cinematic in which the camera slowly trucks through the corridors of High Charity, infested by Flood biomass. We hear the Gravemind say "Now I shall ask, and you shall answer" addressing Cortana. We understand that she's his prisoner, and there's a risk she might leak humanity's best kept secrets.
She goes "Alright. Shoot." in the sense "ask your questions". But in the french dub.... yes, they literally translated that line as "tirez" -meaning "shoot", as in shoot a gun!!

This is supposed to be a line heavy with implications, the very last line in the game before Halo 3 would release 3 whole years later, and they rendered it completely meaningless... 13yo me was super confused for years. And it has never been fixed !! to this day she still says "shoot your gun" !! dammit I'm still mad.

To be fair "alright, shoot" is a phrase that came from shooting a gun. In the context of the situation it is understood as "alright, ask," but the situation is as if the question is an imaginary bullet in an imaginary gun. Its not that surprising to me that something like that was translated that way.

before Halo 3 would release 3 whole years later

Man I miss when we only had to wait three whole years

That’s hilarious though

I wonder what the history behind the phrase is.

Still erroneous though... I assume the translation process was made in a vacuum, with no context or understanding of the story.

But it's probably not a French idiom

to be fair, AAA game development has become exponentially more complex (and expensive) since then. I'd hope they get all the time they need, though it rarely seems to be the case today.