why skill calc so wrong?

hello!http://battlelog.battlefield.com/bf4/ru/battlereport/show/1/572461152834016384/325960102/

I don't really understand why this happens, this skill calculation?

I didn't even go in the game, however, receive -27 skill. Maybe it's time to consider such moments?

I think it's not very fair if I didn't play should be zero and not be counted in the statistics..