BUG: One game cost me a full rank?

I just went from 1 game away to promotion match, to a demotion match.
One game, we lost and it said -200 points… but started subtracting points from a level way below what I was when I started the game. What the heck happened? The game before was fine! I had two, 1 seconds disconnects in the game… it doesn’t happen often and it didn’t result in deaths. I apologised anyway. Dose this costs you a full rank somehow?? The hell just happened? O.o

If you miss a draft you lose 600 rank points. It sometimes doesn’t load till you’ve played another game or restarted HOTS.