So, basically, your baby's father knew the guy who he is accusing of having performed the robbery, confessed to being a participant in the crime, and has a history of similar violent offenses, and his actions were caught on video? I can see why he's considering the plea bargain.
He can discuss the circumstances of his confession with his lawyer. Being drunk isn't of itself going to get the confession suppressed.
You're stating that your baby's father was given a six year plea offer, turned it down, but now that the prosecutor has video demonstrating his complicity in the offense they're asking for eight years? Presumably your boyfriend's lawyer has the video, and presumably if the prosecutor had obtained and reviewed it at the time the earlier offer were made the initial offer would have been for eight years. If you mean something else, please explain.
He can discuss the chances of a better plea deal with his lawyer.

