As a cheater at USC, hat tip to Diderot, ESPN has documented his tenure there via 30 for 30 viewing. Briefly, he was suspected of using questionable, i.e. illegal recruiting enticements in violation of NCAA rules, never adjudicated his personal role in the matter. On that, he conveniently skipped town just as the NCAA began its investigation of the Trojan program that subsequently placed them on probation, restricted TV appearances, eliminated Bowl participation briefly and reduced the allowed scholarships. Also rescinded and repossesed Reggie Bush Heisman. Took his job with us at that point in time. NFL circles dislike, or resent his so-called unearned head coaching jobs in New York and New England. NFL coaches are a jealous lot, especially if they believe someone hasn't "paid their dues" before becoming head hombre. It's all pretty petty stuff, except the NCAA violations, which many believe he turned his back on the college program and ran into the waiting embrace of Paul Allen. That's my take on his popularity, or lack thereof, within NFL boys club.
Personally I'm grateful he's our coach. I was raised to root against USC being from here and credit him with the Seahawks ascendancy. Also I am genetically predisposed to favor his leadership of the Hawks in my household. I like him here and can easily overlook his sometimes overblown sense of righteousness. I am certain he is resented in some NFL circles, including the referee brotherhood, probably for reasons only they can fully explain. The vitriol among other fan bases is decidedly negative towards him and usually is centered on his failure to stay and face NCAA investigators. He was clearly enemy number one among Husky fans during his tenure in the Pac-12, or 10 while he was there.
Regarding the Lane ejection, the NFL levied no fine in their weekly review of significant plays/hits/penalties. Although no declaration was made by the official review, not fining Lane is generally viewed as NFL agreement that nothing egregious occurred, like a punch. In his weekly press conference Carroll declined to elaborate but did say his conversation with the NFL was significant.