1. The argument for it being framed for political reasons is very weak given the evidence they have.
2. You haven't said what the consequences would be for the prosecutor. Worrying about institutional consequences down the road is not the MAGA way. So I'd want to know if the prosecutor would face any personal consequences. Without that, I'd be reluctant to say zero chance.
3. Who is the trial judge? Does that person have any integrity? My view of judges in places like St. George Utah is dim. I've read too many cases (doing research for my own family law case) showing small-town judges behaving in shockingly unethical fashion. Or if not unethical, shockingly credulous and ignorant.
So I wouldn't count on the trial judge being angry as a deterrent, unless we know more about the judge.
4. As I said before, if this was the FBI document, I would take an even money bet in a heartbeat. That this is a different office would substantially reduce the likelihood, based on the information we currently have available. But unless there is personal consequence to the prosecutors or a realistic chance that the case would be dismissed, I don't think we can dismiss the possibility.
5 Again, this isn't just a matter of questionable falseness. Those texts are OBVIOUSLY faked, like 90%+ chance. The only question is whether the kids faked them in order to absolve one of them, as per theories floating around, or law enforcement faked them. They are too formal and explanatory even for them to be MY texts, and I'm a guy who separates texts into paragraphs.