The collision only counts for the guy on who's FE it happened.
In your examples you are doing the right thing in trying to avoid the collisions, but they are still happening on your FE. On the other guy's FE you might have been as much as 200 yards apart, and it wouldn't be fair to him to die for no apparent reason.
The reason for the differences is internet lag. There is no possible fix for it.
The collision system in AH is not perfect, but it is the best comprimize for the imperfect technology of the internet.