750 milliseconds is quite a bit of time. about 3/4 of a second if im not mistaken. I was barely lagging at all. If you watch the killcam closely, I was standing about where I was on my screen as I was on the killcam. That is just class A bs because of how easy it is to quickscope. 99% of people will agree I should've won that gunfight.
From your perspective I agree you should have won that gunfight; however, it's the host's perspective that matters. If he was using any AR or SMG, the results would have been the same. The OHK weapons make it easier to see connection issues. This means every time you're behind a guy quickscoping, you remember every kill. Selective memory also plays a part towards the negative views of quickscoping. Most people remember the 2 deaths in a match, but are quick to forget the 5 kills against the same guy.