The Patriots say theirs were, too. The NFL took responsibility for the breakdown, saying it controls communications equipment, including headsets, for both teams.
Steelers coach Mike Tomlin said after the game, a 28-21 Patriots victory at Gillette Stadium, that Pittsburgh's coach-to-coach headsets picked up New England's radio broadcast for the majority of the first half, preventing his staff from communicating with each other. Yahoo! Sports, citing an unnamed source, reported that the Steelers will file a complaint with the league about both the equipment failure and officials not turning off headsets on both teams' sidelines.
Friday morning, a report on Steelers.com, the team's official website, said that whenever an NFL representative was on the Patriots' sideline, the Steelers' headsets cleared, but when the representative walked way, the game broadcast returned. ESPN has not been able to independently confirm that report, which was unattributed.
A source with knowledge of the NFL's reaction said Friday morning that when the league determined Pittsburgh's communications were down, it was in the process of shutting down the Patriots' headsets when the problem was resolved. The problem resurfaced briefly, but was then resolved and did not recur.
The NFL released a statement Friday morning explaining that coaches' communications equipment, including the headsets, is provided by the NFL for both teams' use on game day, but that the home team "is responsible for the installation and maintenance of that equipment."
"Every team's game day communications personnel are required to work with the NFL communications consultants to ensure wireless equipment is free and clear of interference and address any problems," Michael Signora, the league's vice president of football communications, said. "Technological and stadium infrastructure issues of this type happen at many stadiums around the league and whenever there are issues of this nature, we do a thorough review."
Signora said Thursday night that the interference in coaches' headsets was caused by a stadium power infrastructure issue in Foxborough.
When pressed after the game, Tomlin said headset issues have occurred repeatedly in New England.
"That's always the case," the Steelers coach said. "Here?" a reporter asked. "Yes, Tomlin answered. When asked if he got a satisfactory resolution, Tomlin said: "Eventually."
Tomlin is a member of the league's competition committee.
Because there wasn't a complete system failure, New England's coaches were not required to shut down their headsets during the repairs. However, the Patriots said they experienced issues as well.
"We had a lot of problems," Patriots coach Bill Belichick said Thursday night. "We had to switch headphones a couple of times. The communication system wasn't very good. We deal with that, it seems, weekly.
"They told us they were on the verge of shutting it off, but then I guess they got it working. I don't know, but it was a problem the whole game. We almost had to switch helmets with [Tom] Brady there at the end. Couldn't get the plays in to him. It was a problem all night."
On Friday, Belichick spoke on a conference call and was asked about Tomlin's "that's always the case" in Foxborough remark.
"I'm not going to get into a back and forth on this," Belichick said.
Asked if his team has the same issues on the road with headsets, Belichick said, "Yeah, I'm focused on the game here. I'm not going to keep talking about it. I'm really not."
All of this led to another controversy involving the NFL, the Patriots and Gillette Stadium on the eve of the first full weekend of NFL games.
Green Bay Packers coach Mike McCarthy was asked about the matter Friday and said, "I think anytime you compete in this league long enough there's things that go wrong and you adjust. It's definitely not the first time [headset issues have] happened in a game, and I'm sure it won't be the last."
The Packers played the Patriots in their preseason opener Aug. 13 at Gillette Stadium, the first time longtime assistant coach Tom Clements called the team's plays. After that game, quarterback Aaron Rodgers was asked what he thought about Clements' performance.
"Well, it was a good start for us. Tom was very calm on the headset and he enunciated well," Rodgers said. "We had a headset issue at one point, but that's kind of preseason."
There have been notable instances of headset failures from past seasons:
In the 2010 AFC Championship Game between the Jets and Steelers in Pittsburgh, Jets quarterback Mark Sanchez had trouble receiving calls over the radio in his helmet. At one point during the game, the Jets had to use a walkie-talkie to relay play calls to Sanchez.
In a 2005 wild-card game between the Jaguars and the Patriots in Foxborough, the Jags experienced communication malfunctions between coach Jack Del Rio and his assistants as they tried to send the plays in to Byron Leftwich for much of the first half. Del Rio said he asked officials to take those systems away from the Patriots but was told there was no rule requiring that.
In May, Karlos Dansby told NBC Radio that the headset in his helmet stopped working during 2008 game at New England in 2008 and that he suspected foul play. It was snowing that day and the Patriots won in a blowout.
"My headset was working fine, every game," Dansby told Pro Football Talk. "Until the very last game of the year. We get in Foxborough, they couldn't get my headset fixed, for nothing in the world."