No quitters' score, no penalty.
Regardless of your responsibility, the "disconnection percentage" notes that you did not complete some rounds. It does what it's designed for by WGT (news text from Aug 29):
And to help players decide who they want to play with, we've added a Disconnect % next to player names in multi-player game set-up that shows how often that player does not complete multi-player games.
You won't blame them that more innocent players get inevitable %% drops than quitters and disconnectors, will you?