Cox was at the bottom of the pile. He said he felt someone hitting him and he started "punching" his way out. The officials threw the flag and ejected him, the standard punishment for throwing a punch.
"I must admit I did throw a punch," Cox said.
Coach Andy Reid said, "You should not be punching anybody" when he was asked why Cox made the error. Reid called Cox over on the sideline after the ejection and said, "That can't happen in a game like that."
The Eagles were limited to just three defensive tackles through the fourth quarter and overtime, and Cox is their best run stopper. His absence hurt the team.
"It was real hard to watch the game," said Cox, the team's first-round draft pick last spring. "It hurt me. I can't afford to do that."
Allen hurts hamstring
Safety Nate Allen left the game in the fourth quarter with a hamstring injury. Allen tried playing with the injury, but ultimately he needed to leave. He was replaced by Colt Anderson.
"It wasn't the smartest thing on my part," Allen said. "I probably should have pulled myself out earlier."
Allen said he does not anticipate being out long with the injury.
Gilyard returns punts
Mardy Gilyard was the Eagles' punt returner in place of Damaris Johnson, who was inactive on Sunday. Gilyard found out about his new job early in the week. He returned two punts for 15 yards and called three fair catches. He provided more security than Johnson has demonstrated in that spot in the first five games.
"I think I did pretty good," Gilyard said. "I managed the game the best I could on my end. As a returner, especially a punt returner, you've got to be able to manage the game. You can muff a punt or you lose field position, but all in all, I think I made smart decisions. And when I tried to return, just tried to go vertical and get positive yards."
Extra points
wide receiver Riley Cooper made his season debut. He caught two passes for 18 yards and contributed on special teams. . . . Linebacker Jamar Chaney, who started last week, was a healthy scratch. . . . Kicker Alex Henery converted on three field goals, including a season-long 49-yard attempt. He has made 10 consecutive field goals.
Contact Zach Berman at zberman@phillynews.com or follow on Twitter @ZBerm.