Well Jesus Christ, which is it? Did the prosecution offer the plea because they had too little chance of winning a retrial, or did the defendants accept the plea because they had too little chance of winning a retrial?
The prosecution offered the plea because they had too little chance of winning a retrial, and the defendents accepted it because it was a sure get out of jail card rather than the assumption that they would in fact have their case thrown out at the new hearing. The kind of plea they were offered required them to say there is enough evidence to convict them, so they said it. There was no option 3: Get out of jail but say that there is no evidence against them.
To be honest, I'm having a little trouble understanding why you are having such a hard time understanding the logic behind this. It's really not that hard a concept to have to have had this explained to you the number of times it has been.
Then if they were innocent they should have pressed for the new trial and let the prosecution lose or abdicate.
Why you would expect them to have any faith in the justice system is beyond me. Considering how much they have been screwed over, betting their lives on the assumption that they would not be screwed over after decades of being screwed over is not logical.
It is only your
opinion that they
should have done this. I feel that your advice is bad advice that I would not take if I were in their position. Maybe your advice is the more "noble path," but nobility is not something I can feel or touch or experience. Nobility doesn't get me my freedom or a warm bed or my family or fresh air or not under constant threat of prison beatings and rapes. Maybe you would be happy to risk being executed or see your friend executed in exchange for feeling noble, and I can understand that choice completely. But I would rather live.
Pretty much right now your single argument for why we should think they are guilty is that some random guy on the internet (you) says he wouldn't have acted the same way in their position. You have offered not one single piece of evidence for why you think they are guilty other than "I wouldn't do that in their shoes." Yeah, well I would, thus cancelling out your argument, because it shows that what you would do is not the only possible option for an innocent person.
Edit: the above is incorrect, as you also had listed as an argument that they have been convicted before. So you did have more than one single argument. It's just that neither of your arguments are actually evidence.