Take 2 connections, each have a ping of 0.1 secs. At 300 mph your travelling around 425ft per second.
So if both guys are flying towards one another we get a discrepancy of 170 feet between the front ends (425 *.2 *2 [closure speed =600mph])
This means that in a stall fight where the speed difference is say 30mph, you'd still be out around 9 feet or so. Now, I think AH does some pretty nifty prediction stuff but even so if you hit a guy, or it seems that he hit you, this does in no way imply that the other chap saw the same thing.
It's kind of like the gunnery: you see your shot lands = damage to them; you see yourself hit another plane = damage to you. It would be far worse if you took avoiding action and ended up dead all the same because the other guy "saw" it happen.
What is critical to this is the actual speed of your plane and theirs. Say you're going up on a rope and are just at the top of it flopping over and there's some guy coming barreling in on you at 400mph. As you're effectively not moving, his front end has a pretty good handle on where you are, or the lag results in very little discrepancy to where you see yourself. You, on the other hand, have a different picture. Your front end could well be showing this guy 200 feet behind where his front end knows he is.
So if you hit him, he wasn't there (as far as he's concerned), and if he hits you, well, it will look a bit odd seeing this plane blow up for no apparent reason, but a kill's a kill hey: wow didnt' even need any ammo for that guy!:)
Note: this also explains those "wtf bs" impossible angle shots that someone might get on you - for them it's a slightly different picture.