On first-and-10 from the Jets' 35 early in the second quarter, Mendenhall gained 9 yards to the 26. After momentary confusion as the chain crew began moving the sticks, referee Peter Morelli's crew put the ball down at the 25 and signaled a first down.
The statistics crew hastily awarded Mendenhall a 10-yard carry -- an extra yard that wound up giving him a 100-yard game. The Steelers went on to score a touchdown on Ben Roethlisberger's 9-yard pass to Matt Spaeth.
Mendenhall wound up with 100 yards on 17 carries, rather than the 99 he actually gained.
Tomlin said the Steelers benefited, but he added that the spotting of the ball is always tricky, even if it shouldn't have been in this situation. CBS cameras clearly showed Mendenhall coming up short on the play.
"They spotted it as a first down, and, in that situation, it worked in our favor so we moved on," Tomlin said. "I did think he was a yard short."
Mendenhall is seventh in the NFL with 1,173 rushing yards. He averages 83.8 yards per game.
Copyright 2010 by The Associated Press