From the trainers site.
"Impossible" Shots
Another phenomenon caused by lag is taking hits from "impossible" angles or even after the attacker has already passed you. While more of an annoyance than a contentious issue, understanding how it happens can help you defend against it.
As already discussed, lag causes a different reality on different front-ends. This difference in reality can allow an attacker to shoot when the defender thinks he is safely outside the attacker's line of fire. Unlike collisions, if you opponent scores hits on your plane on his front end, the damage caused by those hits is assessed against your plane. Again we are only talking 1/10’s of seconds and a few extra feet of maneuver space, but it still may be the difference between having a shot opportunity and not having one. This is also how you can get shot after you have passed. Once the host receives hit data from Player 2's front-end, it sends the pings and damage to your front-end - all after you saw your opponent pass you!
This has been described as being like you are towing a target behind you. You can't see it but the enemy can and, if the enemy shoots the target, you take the hits! You can defend against this, though, by paying attention and getting a feel for the angles that people can get hits on you. Once you know this, you adjust your thinking accordingly.
