One of the key facts is that Petrino initially lied about who was involved in the motorcycle accident. Petrino wasn't the only person who tried to cover up the story, though. As noted in the Arkansas Democrat-Gazette (via Chris Bahn of ArkansasSports360.com), the couple that transported Petrino and Jessica Dorrell from the scene of the accident also kept quiet.
Initially, the couple that transported Petrino and Dorrell from the scene - to a rendezvous point with State Police Capt. Lance King - told reporters that Petrino was alone. Only after seeing the accident report did they admit Dorrell was in the car. Family members are now acting as spokespeople for the couple, who seem to have gone into hiding.
It's unknown why this couple decided to back up Petrino's lie. The couple has reportedly gone into hiding because of the story.