San Diego scored 2 td's, 2 fg's, and moved the ball from about their 10 to midfield pinning the Bills back around their 10 on the only drive of their 1st 5 they didn't score on. In those drives they had 4 - 20+ yard plays. Scoring on 4 of 5 drives, each starting inside their 25 indicates they were hitting on nearly all cylinders.
Little reason to believe the Chargers couldn't have scored more if they didn't go ultra conservative w/ the 17 (subsequently reduced to 10) point lead. Even if EJ had picked it up, penalties, lack of stopping SD on 3rd down, and giving up huge plays would have likely still given SD the win today.