Denver Broncos coach Mike Shanahan has been fined $20,000 by the NFL for his public criticism of game officials following last Sunday's 20-17 victory over San Diego. The fine, which had been anticipated, was confirmed Friday by a league spokesman. It is believed to be the first such sanction against Shanahan during his NFL career. Shanahan was critical of officials for negating a 61-yard punt return for a touchdown in the fourth quarter of Sunday's game. The score was nullified when game officials flagged Denver for having too many players on the field during the runback by rookie cornerback Darrent Williams.