The most telling words in the NFL’s latest officiating brouhaha came from referee Ron Blum during the Steelers-Titans game.

“I don’t believe that’s a challengeable play, but I will check,” he told a national audience when Pittsburgh coach Bill Cowher asked for a replay review of whether Derrick Mason’s knee hit the ground at the start of a long punt return.

It turns out, Blum was told, that it WAS a play that could be challenged, just as Cowher argued.

Thus did Week 2 of the NFL playoffs start the way Week 1 ended: With questions about the men in black and white stripes.

And there were questions right down to the penultimate play of Steelers-Titans. That’s when a running-into-the-kicker call negated a missed field goal by Tennessee’s Joe Nedney and allowed him to kick the winner in overtime.

That won’t elicit the “mea culpa” statements from the league the way the errors in last weekend’s Giants-49ers game did, but it’s another indication that all is not right in the land of the zebras.

NFL spokesman Greg Aiello said Sunday that supervisor of officials Mike Pereira had determined that Blum’s eventual decision on Mason’s return and the late penalty call both were correct. Despite Cowher’s anger, there are unlikely to be any further public statements.

From Cowher’s perspective, the question was whether the penalty that gave Nedney a second chance should have been called in OT of a playoff game.

The kicker’s comments afterward didn’t help.

“After I retire from kicking, maybe I’ll take up acting,” he said with a smile after clearly taking a dive when brushed by Pittsburgh’s Dwayne Washington. But as Pereira determined, even if it wasn’t much of a hit, it’s still defined as a penalty.

More disturbing was the admission by Blum that he didn’t know what is reviewable and what isn’t. To his credit, he took the advice of Cowher, a former chairman of the rule-making competition committee, and checked with the supervisors in the press box.

Back judge Perry Paganelli and referee Ron Blum (7) confer on a call. In order to answer questions surrounding officiating during the NFL playoffs this season, refs have been instructed to confer more frequently -- as was the case in Saturday's Titans-Steelers game in Nashville, Tenn.

Then Blum reviewed the play and agreed that Mason’s knee had been down at the beginning of his return.

Strange happenings: A coach tells a referee the rules, instead of the other way around. Especially a referee rated high enough among his peers to get to work a playoff game.

Also strange: Pittsburgh linebacker Jason Gildon’s claim that he asked umpire Chad Brown for a timeout by name — “Chad, timeout!” — and Brown told him the Steelers had none left.

They did have timeouts, but Blum said after the game the call came too late — after the play had started.

Maybe the system is flawed.

One problem with officiating during the playoffs is that the crews are so-called “all-star” crews: Men from different groups who haven’t worked with each other during the regular season.

That could have accounted for the mixup at the end of the New York-San Francisco game, when the league acknowledged that pass interference should have been called, and the Giants should have had a second try at a game-winning field goal.

The solution by the league was to order more in-game conferences among the officials.

That led to two games Saturday that took well over three hours each.