Scoreboard is very inaccurate

I just joined a BTB game on exile and it said I started the game with 3 kills and 8 deaths, but when I looked at it in theater I only had 1 kill and 0 deaths (because it was join-in progress.) The final score that I had was 4 kills (which I don’t know where that even came from) and 8 deaths even when I never died once. WTF is this?

There have been times for me when my kill count in the post-game carnage report was more or less than the amount of kills I had shown in the scoreboard just before the match ended. Very strange indeed.