He could have gotten off at the time if he'd have come clean and cooperated. Baseball wasn't out to get him. Pete was into some very bad shit and didn't want it to come out. He felt it was better to fight and play victim and do his auto signings at casinos and such. There's strong indications that Lenny Dykstra did similar things but he admitted to it and baseball worked with him. Don Zimmer too.
Pete smeared Giamatti, Vincent... said he didn't bet on baseball, then it was baseball but not the Reds, but yes, it was indeed the Reds.
Again... when an agreement is and the person agrees to the maximum punishment... doesn't pass the smell test for a guy claiming to be innocent.
A guy on charge for 1st degree murder facing life in prison accepts a plea deal.... for life in prison.... it means he didn't want a trial and certain details to be exposed.