It would be hilarious if motion sensors looked like little mini campfires.
Dude this happens with me and my friends. I have a brother in law that is a IT guy. We've talked about this before and he told me that online gaming not only depends on Internet but your TV/ computer screen. So according him if some ones screen refreshes at a faster speed they are actually seeing first. So all the times that you are shooting someone and they turn around and kill and on the kill cam it doesn't show you even firing this could be why. If this is correct. He also said its more likely if the other person has their system hooked up through a computer screen. I don't know if any of this is right I'm not the IT guy I'm just passing on something I herd.
P.S my best friend calls them rubber bullets.
I know sometimes I use a butter knife. I have litteraly taking 2 or three swipes at a guy before I decide to just shoot him, but usually by that time he somehow fires sideways and gets me with a one shot kill. I just love being shot by a guy not facing me at all.