There is an appeal/protest process but it has never been used. The NFL would force a replay of the game either in it's entirety or force a replay from the time of the call in question. Obviously, you can see why something like this is unlikely.
As an example for those that remember, back in 2003 the Giants and 49ers had a playoff game. SF was up by 1 and the Giants lined up for a FG on 4th down. Basically all h*ll broke loose and the holder for the Giants chucked a desperation pass into the endzone which fell incomplete. It was obvious that offsetting penalties should have occurred and one more play should have been given to the Giants by rule, but only a penalty on the Giants was called and the game ended. The next day even the officiating crew admitted 100% they had made an error because of the chaos and confusion. But even that game was not replayed, and it would've have only been one play and it was a playoff game.
So considering that occurred and was not replayed, I see little chance that the Chargers can or even bother to do anything.
My Playoff Team - Please Comment
MSchaub, DMcNabb, JFreeman, KKolb
SJackson, THightower, CWells, JForsett, JSnelling, CJennings, QGanther
RWayne, RMoss, RMeachem, MCrabtree, DBowe