"Your behind first" meaning

[AISguy]

Hi everyone!

I got a DC, to the member of other team (ziegest).
As a reason for not the enemy but me to Alt+F4, the player "Defcon52" said those lines:
"your behind 11"
"4 behind ziegest"
Then he also said "Your behind first" (not shown in the replay).

In order to not irritate other players, I Alt+F4'ed right after those lines.
What's the meaning of the Defcon52's lines? Can you tell me, please?

(replay and match data attached)

[biass]

To be "behind" in this context is to be behind in data packets in the f11 screen on the top left

however "your behind first" is probably untrue, he claims you were behind in data packets before <his teammate> and thus blames you for the lag, so you will quit and not <his teammate>, giving his team a player advantage