How do you catch and throw plasma grenades in halo 3?

[juicebox]

ive seen videos on youtube about how you can get a plasma grenade and your opponent will CATCH and THROW the same grenade back at you. how do you do this??? for more info, go on youtube and check it out for yourself...

 

[kimmermer]

It can't be done, they must have just caught and throw the grenade at the same time.

 

[Matt]

It's a glitch. Right before the grenade lands in your hand, throw a grenade of your own. if you're lucky, you'll throw it back.
cheers