Currently (as of 03/20/16) when a player quits during a war - all skulls (s)he won in this war are deducted.
Probably the idea was to prevent “quickly get some skulls and exit before could be attacked” stuff.
But now - other alliance members look at skull count and get idea “we’re sure to win; I don’t have to fight too hard, spend gems on Scrolls & Resurrections …” …
And suddenly - some skulls are deducted - we’re not winning anymore ?!
Keep all skulls won, BUT allow the player who quit (or was expelled) during a war to be attacked during this war.