I played a co-op adventure game on Airport with two random people. One of them was doing a glitch I had never seen before that I can't find any information on. He basically was able to walk around like he had the juggernaut medal kickback, even though that wasn't his actual kickback. I know it wasn't his kickback because he activated Army of Three during the game.
He seemed to activate it by doing something like raising his Arm-Micro, dropping it, and then he'd suddenly be walking around with the same animation as you would if you had Juggernaut turned on. I've been searching around on Google and Youtube to no avail. Do you any of you know how to do this? He was basically doing it on command.
Hold L1 and then hold UP on the DPAD, It's like the situational awareness pose from U2.
Before you try it on Deathmatch or something, it only works on Co-Op.
These two have the answers you are looking for. All you need to do is hold L1 and D-Pad Up in Co-op. This will not work in any Competitive game modes, however.
Bunshing, D-Pad means Directional Pad, meaning, the arrows on the left side of the controller.