NFL: Gene Steratore using index card 'very unusual,' but within rules

Referee Gene Steratore's decision to use an index card while measuring a key first down Sunday night was "very unusual" but did not violate league rules, an NFL spokesman said Monday.

Steratore, who has been a referee since 2006, used what appeared to be a penalty card to measure the distance between the tip of the ball and the pole at the end of the first-down chains. He determined that the Cowboys had in fact converted a fourth-down attempt, extending what turned out to be Dallas' winning drive in a 20-17 victory over the Oakland Raiders.

Raiders coach Jack Del Rio said afterward that he saw "air" between the pole and the ball, even with Steratore's card in between. But speaking afterward to a pool reporter, Steratore said he used the card only to "reaffirm" his visual decision.

"The ball was touching the pole," Steratore said. "I put the card in there and as soon as it touched, it was nothing more than a reaffirmation. The decision was made based on my visual from the top looking down and the ball touching the front of the pole."

Del Rio was still upset on Monday.

"The guy ran out there with the camera, and put the camera right on it so the whole world got to see what it was. It's not like we're making something up. The guy with the camera was right there. So how you can look at that and get up with a smirk? I don't know. That's hard to take," he said.

Del Rio said he did not see Steratore pull out the index card, but the Raiders coach did see the ref's reaction and smile.

"It's been tried and true -- just stretch the chain and inside, if there's space, it goes the other way," Del Rio said. "I mean, I thought everything was in place to get an accurate call and I saw space, and in my opinion, it should have gone the other way and [been] a turnover on downs.

"I saw the chain and, again, like I said, I saw space and I was like, 'All right, [Dallas] just made a big error going for it right there and this is a turning point.' Four-and-change [on the clock] in the game and we've got the ball on the 40 going the other way. I mean, that was pretty ballsy and it really didn't work. Except, they got the fortuitous reaction from the [officiating] crew."

The incident rekindled debate about the antiquated and at times arbitrary way the NFL measures ball placement on the field. NFL referees place the ball directly below where they believe it was when the ball carrier was down by contact.

Linked chains are used to measure spots when the ball is close to the line to gain a first down. Generally speaking, referees are asked to make the decision based on visual evidence, but nothing in their guidelines prevents using a piece of paper to create a visual plane.

Referee Bill Vinovich did the same thing in a 2013 game between the Cleveland Browns and Baltimore Ravens. The NFL issued a similar statement at that time, calling it "very unusual" but within its guidelines.

ESPN's Paul Gutierrez contributed to this report.