Actually I can usually tell when it's me or when it's the server. After a time of doing this sim you just start to KNOW when your shooting correctly and should be hitting.
The view is just as it should be and you have the correct angle you need and the con is right there at less then 200 yds and the sight dot is right where it should be and his wings fill your site picture and u pull the tirgger and you lite him up all over his cockpit, or his wing, or his tail section, and..... OR the con has suddenly moved about 30 ft in whatever direction and..... OR you don't see any hit sprites and....
....... the con keeps flying and you find yourself saying WTF??????????
Could be 2 things in my expierence.
1 is connect issues
ie packet loss (with udp this can be a problem as it's not always resent so the server never gets the info so the con never gets the info it has been hit and just flys on?)
Sadly not allot can be done about packet loss in some instances. A DOS attack or something can come along somewhere within the server hops your connection is using

2 corrupted file
ie the AHII front end on your machine could become slightly trashed and not give all the info to the AHII server.
What i've done whenever I have a lockup that requires a shutdown reboot is uninstall AH and reinstall it. Had this problem from time to time with AHI and it seems it carries over into AHII with my system. Don't know if it affects others this way. But had a squadie that was havin really bad connection speed varience issues and he finally fixed it by totally removing AH and all the AH folders, I mean everything that had anything to do with HTC was taken off his machine, and he started completely over with a brand new install etc. and it fixed it. He has cable BTW.
I get tired of really lighting up a con on my FE and it then flys away no damage
Also don't care for having to use 1/3 to 1/2 my ammo on one con that i've already hit pretty hard once and have to hit him again and maybe even again

When this starts happening I relog and check my ping then come back in. If it continues over a longer period of time I remove and reinstall.
Ya ok maybe it just happens to coincide with the net freeing up or somethin but it works as far as i'm concerned.
Note: saw on a news service there is a new "MyDoom" out there that actually porked the Google search servers for awhile!!!!!!!! It is reported that it started at around 9 AM EST this Monday!