The state won't retry. He's going to walk. Good for him. Who knows if he really did it or not, but the evidence against him was sketchy.
You say that like it's a fact. What's your evidence?
If they retry what evidence will they bring to the table?
It wasn't a felony murder, so it can't even be tried in a different jurisdiction (federal). The protection isn't altered when new evidence comes to light.
If the retrial doesn't happen soon (rather, soon after the appeals process is done), the State will be obliged to release Syed. Actually he might get bail in the meantime anyway.
I think you're right though. If they do appeal it and fail they'll just let him walk, but are going to continue to this as long as they can to keep him in there as long as possible.
Beyond that? The evidence against him was a good deal less sketchy than Serial made it sound, but I still don't know if it would be enough to get a conviction sixteen years later.. so who knows.
That said, let's just start with the central premise of Serial E1: that it's hard to remember details of a day six weeks before, and that's why Adnan has trouble telling the cops what he needed to know. Remember, this is a day when his ex-girlfriend disappears and a police officer called him about it, but we're supposed to assume that nothing in that series of events is a big enough deal to stamp a few things (even just things related to Hae) in his memory.
Furthermore, if we assume that it's easier to remember something that happened same-day, we can assume that he asked Hae for a ride home from school - per what he told the officer the day of - something that he now denies. He did this, of course, despite the fact that he had a perfectly working car in the school's parking lot at that moment.
.. and so on. Like I said, it's really hard to start dealing with all of the claims made by various people at various times, but there's a number of ways to view the facts in a (to paraphrase Sarah Koenig) "bad for Adnan" way that aren't at all sketcky.
The problem (and the point I'm trying to make) is that there's this sort of "Adnan was convicted by bad evidence" type of myth that the entirety of the Internet seems to believe because that's what a podcast says. In reality, a jury of his peers, after listening to the case in full, decided to convict the guy. Unanimously. I don't know if the guy is guilty or not, but it hits me as a little silly that the entire world has decided that they know better than the jury because we listened to a podcast. There's at least some reason to read that as "Serial didn't provide a totally unbiased story" not "wow, it's good that we are all so much smarter than the people who looked at the evidence in its entirety in the courtroom".
I disagree. I think Serial made the evidence seem stronger than it turned out to be.