Replacement officials admitted making two mistakes in Minnesota's victory over San Francisco on Sunday, while several other games included suspect calls that could have affected the outcomes.
Referee Ken Roan said he twice granted 49ers coach Jim Harbaugh challenges after Harbaugh called timeout in the fourth quarter. Neither challenge should have been allowed once Harbaugh asked for time.
In the Lions-Titans and Bengals-Redskins games, officials marched off too much yardage on penalties.
Lions LB Stephen Tulloch's helmet-to-helmet hit on Craig Stevens wound up as a 27-yard penalty, while the Redskins were penalized 20 yards instead of 15 for unsportsmanlike conduct in the final seconds of their loss.