I don't have a video of it but I once double-jumped into the air next to an enemy hunter who did the same. As I was pointed directly at him and he apparently was looking in a different direction, he was not able to melee me while I still had gear that gave me a faster melee. I knifed him twice in a row while we were still in the air so that when we fell one hunter landed on his feet and the other landed on his face. Two guardians go up, one comes down.
Got almost the same experience!
My Hunter was engaged in a fierce firefight with a Titan over C in Rusted Lands. We ended up right next to each other at point blank range. We both ran out of ammo at the same time and had the same stupid reflex: JUMP!!!
We stood there, suspended in mid-air, not a meter apart, for a second or two while he desperatly tried to reload his Shingen Assault Rifle.
Then I knifed him. Twice!!!
Which only goes to show that what goes up doesn't always come back down...