Shouldn't the league be more on the case of the refs than Tomlin? If they had called a penalty on the play and awarded a TD for coming on to the field to stop a breakaway TD, things would have resolved themselves on the field. Then any future impact would be out the window.
The league generally does not wish it's referees to set new rule precedent during games with "gray areas" in the rule book/new type dilemmas. This is for several reasons. One, the league generally vests this with the league administration and it's competition committee. Second, it opens up refs and officials to more possible outside influence/infiltration. This is a major problem in the NBA that the NFL does not wish to duplicate. Third, NFL officials have long held the stance that they prefer to stay out of any issue that deals with the legislation of the rule book. NFL officials do not want to be embroiled into issues regarding league politics and the league and players union don't want them in that role either.
I highly doubt the league sanctioned or fined or formally punished any member of that crew. The leagues goal is not to be punitive to their refs ( the NBA does this to a very debilitating effect to how the games are officiated. ) because it would incite widespread retaliation against specific coaches and players. NFL refs are their own small fraternity/inner circle, no different than NFL players have their own circles in their own locker rooms. While NFL refs might not love or like or even respect each other in their own circle, if you screw with one, they will, like any other niche closed off group, tend to close ranks.
Focusing on the refs instead of Tomlin makes this a bigger mess for the league from a PR standpoint, it also gives Tomlin a safe target to deflect blame, but it would, long term, cause massive ref based retaliation against the Steelers and Tomlin and the organization.
Sometimes the price of objectivity and neutrality is knowing when and where not to get involved. I don't have a problem here with how the refs handled this or the call they made, it was a very difficult situation for them and leaning in one way or another would have had a detrimental impact on the long term goals of proper and effective officiating.