It depends. Was he ordered to go to rehab as part of probation, as a condition of pretrial release, or as some sort of diversion program? If it was a condition of probation then he may violate his probation and will have a hearing on the issue. If he is found guilty of the violation of probation then he can be sentenced up to the maximum. If it was a condition of pretrial release then he may go to jail until the case is resolved. If it was part of a pretrial diversion program then he likely won't go to jail but the case would be kicked out of diversion and set for trial.
It's impossible to say whether the program would accept your son back into their program. It probably depends upon what kind of dishonesty is involved.
This is not to be considered legal advice nor does an attorney-client relationship exist.
I have edited the area of your question to criminal defense as your question suggests that your son was facing criminal charges. A criminal defense attorney will get this question in hopes that it may be answered for you as it does not present a professional ethics question. You son was discharged for dishonesty which is something the court will address at some point.
The hiring of an attorney is an important decision that you should undertake with careful considerations. The use of Avvo, Inc.'s question and answer forum is only to provide general information and in no way forms an attorney-client relationship between the you and the attorney answering your question.
Don't you think it would be best to speak with the attorney who represented him? He could be in a world of hurt here, but we do not know enough to say how much. It might be time to hire a private criminal defense attorney.
R. Jason de Groot, Esq.,