The bottom line is that your Fiance needs an attorney. He needs an attorney before anything else happens. Is is possible for the case to be dismissed? Maybe; but do not count on it.
The information your listed is certainly mitigation, but it is not a defense. If your Fiance has counsel, his attorney can explore all the options in the case, including speaking to you, if you are willing, to try to get the best possible outcome.
Especially with no record, your fiance might have a case that should go to trial. Only by sitting down with a competent attorney can he really understand all of his options.
Nothing in this communication should be considered legal advice. Nor should this communication lead you to believe that an attorney-client relationship has been created. Only after thorough analysis of your case with you in my office can I provide effective legal advice on your specific issue.