This time, I was the one with the bug - basically I was my own third team. When you are the third team, you can cap both bases, any damage you do is not credited to you and any kills you get are not credited to you. However, the victory XP and C-Bills are accorded to you if your team wins.
This is the evidence.

I was the one who killed Grindmonster, and I was capping the base here...

Observe the 0 damage value. Also, observe how 7 enemies are dead and only 4 kills are recorded on my team.
I killed the other 3. It seems like assist xp and C-Bills are awarded to my team, but nothing is awarded to me.