Recently I was playing around on forge doing the no gun glitch and when I crouched I realised my head was in my stomach area. So I went into theater to see what happened when I looked at me it looked like I was holding an invisible shotgun it was the weapon I picked to start with when ever I hit the crouch button. The crouch button does NOT make you crouch just make it look like you were holding your weapon. I'm not sure how this would fit in fo Machinima but I thought it might help.
Not just that, when crouching without a weapon and moving, you appear as if you are sliding, and you could see that in first person too, just look down.
Get a hologram, rip off a machine gun turret. Jump, Use hologram, and melee at the same time. If it doesn't work, they keep doing it.
Also when you turn your legs just sort of follow your body and get pretty glitched. If you melee hologram off a cliff it's slightly easier.