Just got leaverbuster for dcing?

I'm not sure why this happened but it seems to be a bug, I came back as quick as i could and still won the match but I got leaverbuster for it, seems counterintuitive for something that probably occurs across the board. I got leaverbusted for leaving one game earlier in the week and did my games fine but to get leaverbusted after a DC that I came back from, that doesn't make any sense.