This is a simple isssue. He broke a rule. It was well-documented by videotape and by his own admission when in a post round interview he stated he moved the ball back by 2 yds. His ignorance of his breaking the rule at the time of the transgression and when he signed his card is irrelevant. He should be DQ’d. But he cheats in all aspects of his life, so his remaining in the tournament is par for the course. Pun intended.
His ignorance of his breaking the rule at the time of the transgression and when he signed his card is irrelevant.
Actually you are wrong. According to the article at PGATour.com:
"The decision to assess the penalty -- rather than disqualify Woods for signing an incorrect scorecard -- comes after Rule 33-7/4.5 was changed in 2011 to read that if a player unknowingly signs for an incorrect score he will be assessed a penalty rather than be disqualified."
Woods assessed two-stroke penalty