Bettis told CBS News Correspondent Jeff Glor on "The Early Show" Friday the accusations against Roethlisberger "came as a shock" and are out of character. They're not the Roethlisberger he's known, Bettis said.
He added that a two-game suspension would serve notice on Roethlisberger and the rest of the National Football League that these types of actions are unacceptable, adding that Roethlisberger "understands" that now - and may not have before.
Bettis said he thinks Roethlisberger can repair his image, but it's going to be a "long, tedious journey," since many fans are "disgusted" over to the accusations. "The first step," Bettis suggested, "is for him to change the things he's doing in terms of where he goes and the people he has around him."
The two-time Super Bowl winner learned this week he won't be charged with a crime, but still faces likely disciplinary action by the team and perhaps the league, possibly including a suspension.
Newly-released police documents quote the student as telling investigators in Milledgeville, Ga. she tried to get away from Roethlisberger and made it clear she didn't want to have sex with him.
She says he invited her and her some of her friends to the VIP room at the club, where he encouraged them to down numerous shots of alcohol.
The accuser says one of Roethlisberger's bodyguards "sat me on a stool. He left and Ben came back" and exposed himself. "I told him it wasn't OK. He followed me into the bathroom and shut the door."
Then, she says in the police report, "I still said, 'No, this is not OK.' And he then had sex with me."
Prosecutors say they decided against bringing charges against Roethlisberger because the allegations can't be proven beyond a reasonable doubt.
Ocmulgee Circuit District Attorney Fred Bright also revealed the woman asked him not to pursue the case because, she said, of the publicity. Still, the accuser could file a civil suit if she wants to.
"If she did that," points out CBS News legal analyst Lisa Bloom, "the burden of proof would be lower. She would just have to prove her case by a preponderance of the evidence, which means she'd have to show the jury it was more likely than not that she was sexually assaulted."