The day after the Broncos rallied past the Panthers 21-20 to open the NFL season, helmet-to-helmet hits taken by Carolina quarterback Cam Newton and questions about concussion protocol dominated talk of the game.Newton took four helmet-to-helmet hits, with one penalty called. He was tested four times for a concussion — after the game in the locker room, on the bus, on the flight home and Friday morning at the stadium — and all proved to be negative. He was never tested during the game. In July, the league adopted stronger concussion protocols that included not only an independent neurologist on the sideline but also two spotters in a suite above the field who could signal for play to be stopped so a player could be examined for a possible concussion.Newton stayed in after all four hits. Why wasn't he tested during the game? The NFL said in a statement Friday that medical personnel, including the unaffiliated neurotrauma consultant, reviewed video of safety Darian Stewart's final-minute hit on Newton. The league "concluded there were no indications of a concussion that would require further evaluation and the removal of the player from the game."Panthers coach Ron Rivera said the team followed the concussion protocol: "I'm not going to question the doctors, okay?''Rivera also said because of the 6-foot-5, 245-pound Newton's size, he doesn't draw the flags that smaller quarterbacks do. Newton, who is expected to practice next week as usual, said he doesn't feel he was hit in the head intentionally.