It would be a potential violation of your probation to not inform your probation officer of the police contact. It would be a potential violation of your probation if you did not make a truthful report to your probation officer. These are likely conditions of the order of probation that you originally entered into.
A lawyer cannot ethically advise you to violate a Court order. If you disclose what happened there is a good chance you will face a violation of probation. However, the fact that you disclosed it may mitigate the result of the violation of probation. If you fail to disclose it, and probation finds out about it, you will be violated. Anytime a violation of probation is established, you are at the mercy of the Judge assigned to the case.
If you are violated on your probation you should seek the help of an experienced criminal defense lawyer.
In reading your question and the responses I am left with a few questions:
Did you tell the officer that you had consumed any alcohol? If you admitted to having consumed alcohol, or having been in the presence of someone who was you have admitted to committing a violation. If that is the case the officer likely has contacted your probation officer about the violations.
A condition of your probation requires that you submit to searches of you person upon request or otherwise be in violation of probation. If this is all that happened and you were let off I don't advise that you make a full admission to using alcohol and open the door to a violation of probation.
You should contact the PO immediately and advise of the contact with the officer. The extent of the other details that you should divulge is tailored upon what information you have already admitted to. You need to consult with a defense attorney to help you understand what type of potential issues you may now have with your probation.
this is a gray area as you are required to report this type of "violation" when on probation. However, I do not believe reporting is necessary in the scenario above. Good luck to you, Gary Fields