Did you submit your appeal REQUEST?
You'll get a hearing notice. Unless the hearing notice has an issue for "false statement," then you don't have to worry about this at all. There's really no point in addressing it now because it could end up being a total waste of typing if it's not on there.
After you receive the hearing notice and if it's not too inconvenient, go view the hearing file (or if the woman working the counter is in a good mood, you can walk out with a copy) 3 days before your hearing assuming it's an in-person hearing. That will give you plenty of time to see all that you are being accused of and think about how your employer is going to actually prove it or what you can say to make it not sound like misconduct.
No, it's really not. You were fired because it sounds like you were accused of insubordination. If the employer fails to meet their burden at the hearing, then you win. You don't have to propose some alternate reason for your termination that you think sounds less bad. You can't prove that is why you were fired, and if the employer appears, that's probably not the direction they're going to go. Only deal with that one thing of which you've been accused.

