My name is***** have over 16 years experience in the law. Should you like to chat on the phone I am happy to for a nominal cost. Let me know at any time during our question and answer session if you are interested I am happy to give you more details.
The process to convict a person of a violation or a crime requires "due process"
They must give him notice, in writing, of the charges.
So no ticket, so far, is a good thing.
But it does not preclude the state filing charges at some point.
In Ohio, the statute of limitations (the period when the state must file charges) is 2 years for driving while under the influence. So it is certainly possible he could receive notice of the charges in the future, for example by mail.
Bot***** *****ne: the fact he has not yet received a citation
or charge does not mean that they can not prosecute him. It could be they issue the charge at a later date.
Please let me know if you have more questions. Happy to help if I can.