Matt Hasselbeck and Charles Woodson react to the news that four referees who worked the NFC Championship Game are from Southern California. (1:05)

In the latest twist to the still-simmering controversy from last Sunday's NFC Championship Game, there is some concern in league circles about the NFL's judgment in allowing four game officials who live in Southern California to work the game between the Los Angeles Rams and New Orleans Saints, league sources told ESPN.

Those same four officials -- all with long ties to Southern California -- were the ones most responsible for the non-call on Rams cornerback Nickell Robey-Coleman's early, helmet-to-helmet hit on Saints wide receiver Tommylee Lewis that was widely viewed as pass interference. The league admitted to the Saints that it "f---ed up the call," according to sources.

The Saints and other officials not involved in the game do not believe that these officials' geographical ties influenced their non-call, according to sources. Officiating assignments are communicated to clubs on Monday, and there were no complaints from either the Rams or Saints in advance, according to a league source.

But in a league constantly trying to safeguard the integrity of the game, there are some privately wondering how four officials with Southern California roots wound up officiating a conference championship game that involved a Los Angeles team.

There is a perception of bias that the league either ignored or was blind to when it assigned this crew to this game. It ultimately could wind up influencing officiating assignments in the future, according to a league source, to make sure a scenario like this does not happen again.

"The NFL put [itself] in a bad situation," one officiating source told ESPN. "This is stuff that has to be taken care of prior to game. It's just guys not thinking of what's going on, nobody doing their checks and balances. The league is usually pretty much on top of it. This is one that slipped through the cracks."

Referee Bill Vinovich, who led the game's officiating crew, lives in Newport Beach, California. Down judge Patrick Turner, whose primary responsibility was to follow Lewis on the blown call from start to finish, lives in Lakewood, California, in Los Angeles County.

Side judge Gary Cavaletto, whose job was to initially watch outside receiver Dan Arnold before shifting his focus once the ball was thrown to Lewis, lives in Santa Barbara, California. Back judge Todd Prukop, who was stationed in the end zone as an extra set of eyes on the controversial play, lives in Mission Viejo, California.

The Saints declined comment when contacted by ESPN, but others did not.

"I haven't heard anybody say the game was fixed; I have heard people say the crew F'ed up," one high-level league source told ESPN. "But the optic is bad. It's a legit issue and they should have figured that out."

A league spokesman said Sunday: "Officiating assignments are based on performance and not geographic location."

Nobody in the officiating community thinks the site of the officials' residences influenced the non-call; but the idea that all four hail from California left some sources wondering why they weren't assigned to the Patriots-Chiefs game in Kansas City rather than the Rams-Saints game in New Orleans.

One person with competition committee ties said the league needs to take steps in the future to ensure that officials do not work games that involve teams in the states in which they are from and that no perception of impropriety is created.

The league used to routinely ensure that certain referees would not officiate games in which the host was playing in the hometown of that referee. Phoenix resident and former NFL referee Ed Hochuli would routinely not be assigned Cardinals home games, and San Diego resident and former NFL referee Mike Carey would routinely not be assigned Chargers home games.

But for an NFC Championship Game that had a heavy Southern California presence in the officiating crew, there is a sense in the officiating community that the NFL should have taken steps to avoid any perception of impropriety.

In the opinion of many around the football world, this was the most high-profile blown call in NFL history. Turner and Cavaletto were questioned about the call in the officials' locker room immediately after the game by NFL senior vice president of officiating Al Riveron, according to a league source.

After Vinovich told Riveron that it wasn't his play and it wasn't his call, Cavaletto told Riveron it simply was a "bang-bang" call. But then the officiating crew was shown a replay of Robey-Coleman plowing into Lewis before the ball arrived, and the room went quiet, according to a league source. They knew they missed the call.

In another interesting twist, before the conference title game, Rams fans launched a petition to prevent Vinovich from working their team's game because Los Angeles had gone 0-8 in games that Vinovich had officiated since 2012. The Rams were based in L.A. in only the last three years of that span, after relocating from St. Louis in 2016.

Vinovich's regular-season crew -- which features two of the other three officials from Southern California -- also officiated the Rams' regular-season losses this season to the Saints and Eagles, which contributed to New Orleans earning the No. 1 seed and getting home-field advantage in last Sunday's game. In the first Los Angeles-New Orleans game this season, a 45-35 Saints victory, the crew missed a fake field goal spot, and it contributed to costing the Rams the game.

Vinovich's crew called more penalties against Los Angeles than its opponents in all nine Rams games he has officiated. But one source pointed out that, with that crew having worked the first Rams-Saints game of the season, it made sense for it to work the second.

But the NFL also has been more than leery of any perception of impropriety in the past. In 2012, when the league's regular officials went on strike, the NFL pulled one of the replacement officials assigned to a New Orleans-Carolina game after it was made aware that he was a Saints fan. Side judge Brian Stropolo admitted to being a Saints fan on his Facebook page, and he was pulled from the assignment that Sunday morning and replaced with an alternate, Tim Keese, who was traveling with the crew.

This is a different issue for the NFL, but it is likely to trigger more discussion about how the officials assignments were made and how they will be executed in the future.

For Super Bowl LIII next Sunday between the Rams and Patriots, there are no officials with any ties to Southern California or Massachusetts, according to a source.