Arwingpedia says that you can shoot down Bill Grey!
Look at the link:

Bill Grey - Arwingpedia, the Star Fox wiki


     Scroll to the bottom of the page and look for where it says "trivia"
It's the last entry in trivia, here, I'll quote it:


"In Star Fox 64/3DS, if Bill is shot down by the player, he will
     still give his regular transmissions"


     So, does that mean that you can shoot him down?
Or is the information false? I would like it we could shoot down Katt. . .

Sword legion : I noticed this thread but forgot about it..sorry! ^^" Next time I play it i'll make my way to Katina and see if I can make this happen. I'll feel terrible..but it wouldn't hurt to see if its true.

zerothesaint :

That's why I decided to sit on the thread while I played Star Fox.
LOL.

Maybe I'll see if I can do it tonight.
I never liked shooting down allies either.
I really like Bill Grey, he's my favorite character.
So I'm going to try and shoot him down?

XD

You know, if you want, I can go try it for you guys if you don't want to. I'll be a guinea pig, as to say.

I won't mind. Just summon me back to this thread telling me you want me to try.

goodboy :
zerothesaint :





I'm gonna shoot him down before either of ya!
Race time!

Sword legion :

I'll start... Tomorrow morning. Maybe. I'm just tired and want to post as of now, he he.

Sword legion : BRING IT ON, SON!!! I'm firing up my 64 right now!!

zerothesaint :
goodboy :
sonikku :

I. . . I shot him down!
And he was still talking on the intercom!

I. . . I didn't think that it was possible! 

What do you guys make of if?

I know what I'm going to do, I'm gonna shoot down Katt
for flirting with Fox whenever she shows up! XD XD

Sword legion : I went to post that I did it too but then I was like. "Oh wait...I was the last one to post...UGH.." As to make of it? Well...that's Star Fox 64 being as realistic as it gets honestly. Friendly fire is real and it can happen sometimes. It is sad that it can happen but its just another feature that makes the game all the more loveable. It really did its best to keep a realistic form of physics and everything.

zerothesaint :

Yeah, Star Fox 64 did go for realism.
I was thinking that it wasn't possible, but I kept shooting.

Man, it took forever, he has the most health out of any aircraft 
in the Entire game.

Pepper: katina is battling the enemy, will you help em out?

Fox: I'm on my way:

*On Katina*

Bill : Hang on guys, help is on the way!

*Star Fox team enters the scene*

Bill : Fox! you made it!

Fox gets behind Bill and fires rapidly

Bill : Hey! see if I help you again!

Bill : Hey! see if I help you again!

Bill : Hey! see if I help you again!

Bill : Hey! see if I help you again!

Bill : Hey! see if I help you again!

Peppy: Knock it off Fox!

Bill : Hey! see if I help you again!

Bill : You've become quite the pilot!

Bill : Enemy Mothership approaching!

Bill : Hey! see if I help you again!

Bill : Hey! see if I help you again!

Bill : Hey! see if I help you again!

Bill : Hey! see if *crash*

Fox: Whaaa- I. . . I shot Bill down!

Falco: What made you think that you could shoot Bill down?

Fox: I. . . I thought that he had infinite health!

Falco: Oh, that's the perfect excuse to shoot at someone isn't it?

Fox: . . . 

Bill : The hatches are open!

Fox: Oh no! my guiltey conscious is trying to kill me!

Peppy: I can hear Bill in my conscious too!

Slippy: No you don't you old Foggy! He's just fine!
He's on the ground and is using his intercom!


Bill is the second hardest pilot to shoot down in the game.
He uses evasive manuevers when he gets hit. Nintendo did
a GREAT job programming this. Good work Nintendo!

Sword legion : WHO IS THIS BILL TO BE SUMMONED 9-10 TIMES??

Magma_Cube :

Someone who couldn't think of a better username.
He has one post, one thread, and was last active four years ago.

Sword legion : Lol

 <----------------------Originally posted by Magma_Cube------------------------------->

 lol 
 
 <-------------------------------------------------------------------------------------------------------> 
 

 <----------------------Originally posted the rules-------------------------------------------->

1. Spamming – It’s a big no-no here, but what is spamming exactly? It’s when people post things that are irrelevant to the thread’s topic, post very short replies that are under 25 words (and you’ll lose Viz when you post anything shorter than 10 words), copy paste replies or plagiarize, post links to advertise different sites, or create a duplicate thread (a thread that is similar to an existing, active, and older thread).

<------------------------------------------------------------------------------------------------------->


HHHMMMMMMMMM...
 
 

I'm pretty sure. I always tried to shoot down Bill as a joke when I wasn't doing serious playthroughs as a kid, not sure if I ever succeeded though.