The only thing that would cause this would be a difference in the time each of you was in combat. The difference in time in combat could be different start, end times or a death and combat rez.
I suppose that could be it, but nobody died or was combat rezzed, so it would have to be different start/end times for each of us. Very bizarre. Thanks for the explanation
Have you both uploaded to Torparse and checked it there?
In parsec have you checked how long was each fight for you and for him ? Only think i can think of is that you had some debuff on you that stayed longer then the fight itself and that left you in combat for much longer then it actually was. Being able to see it as log on Torparse website would help with that.
If you could post a link to your log and this other sniper, it would be much easier to established what's happened.
I'll upload it once I'm out of the office.