There may not be a bond set. If there is, then he can post bond and be released without going into custody. If there is no bond, then he goes to jail.
Did he get a DWI? Otherwise I do not understand why he was offered (& refused) a breath test, and if he was not arrested, how would his probation officer know that he was offered & refused a breath test.
Failing to report is D U M B. It is the second worst thing that a probationer can do (the first being picking up a new case.) It sounds like he only has 1 failure to report. If so, he needs to get himself turned in ASAP. He does not want to be "on the run" and get caught. The more time goes by, the worse off.
If he gets out on bond, then he may need to address a drug / alcohol issue. If he is using alcohol while on probation, then he may need help. This would help explain his behavior.
All of that said, the first thing he needs to do is hire lawyer to represent him. He will need a lawyer no matter what. Then, he needs to get immediately on cleaning up this situation and getting it straightened out if there is any chance that his probation not be revoked.
Although I have answered the question to try to help you, you should consult with a lawyer in your area in person on the matter. In addition, my answer does not establish an attorney-client relationship between us.
Maybe, but he needs to turn himself in or have an attorney get a bond set on the motion to adjudicate. He needs to have a very good reason for violating his probation terms and not reporting, and just not wanting to face the music will not cut it.
The court has the authority to modify, revoke or continue his deferred but if revoked he will go to jail for the full range of punishment for his original offense.
He needs to talk to an attorney immediately.
Although my intent in answering this question is to aid you in the legal process, my answer does not establish an attorney-client relationship in any way. You should seek the advice and counsel of a qualified attorney in your community to evaluate your legal needs and to advise you. No Attorney-Client Relationship is created without the specific intent of both parties.
Under Texas law, if the probation is a deferred probation, then he is entitled to have bail set on a Petition to Proceed to Adjudication of guilt. He cannot be denied bond unless the probation is an adjudicated (regular) probation, although many judges will set a bond on those cases as well.
He will have to take care of the warrant by turnng himself in. He is best advised to first hire an experienced criminal defense attorney that practices in the jurisdiction where he is on probation to assist him from the very start. Depending on the juridiction and the policies and practices of the presiding judge, the violation if provable can result in revocation of his probation, or sanctions short of revocation.