805.02 Scoring
F. At the end of the round, each player shall sign the scorecard to attest to the accuracy of the score on each hole as well as the total score. If all players of the group agree that a hole score was recorded in error, the score may be changed prior to the scorecard being turned in. Players whose scorecards are turned in unsigned accept responsibility for the scores recorded.
Did Will sign off on the scorecard? If so, he really can't blame anyone else for the error.. also, personally I'd like to see a slight rule change: a scorecard submitted before the 30 minute limit will not be processed until the 30 minute mark if it hasn't been signed by all players. That way, it won't be late (and thus not assessed the -2 stroke penalty for all players on the card), but won't be accepted potentially prematurely either.