Was I charged or detained if the case was dismissed prior to conversion and no judge was assigned for a DWI dismissal?

Based on your question, it seems like you may have been given a citation and charged. Ofter times a prosecutor will take a second look at a case and realize that they do not have a case. In my experience they usually dismiss these cases "in the interest of justice." It is unclear if you were asking anything other than that.

If you were locked up, you were detained. Charges are usually determined at the court level, not the police level.

Typically in order to provide a breath test you have been detained and arrested. It's not unusual for a prosecutor faced with the facts of their case which includes negative urinalysis and .00 blows to dismiss the case. This doesn't negate the fact that you arrested and/or charged.

I just wanted to add that your situation (DUII arrests of innocent people) led eventually to a change in Oregon's Expungement statute -- now, a good lawyer can work to get your DUII arrest expunged, if the case ultimately ended up in a dismissal (not in Diversion, but an outright dismissal). However, the decision of when to exercise the expungement option, and how to go about it, should be between you and a good DUII lawyer. A DA could decide to re-visit the "dismissal" and charge you as long as you are still within the statute of limitations (usually, 2 years from the date of your arrest). For that reason, you'll want to consult a lawyer -- and also because the lawyer can handle all the expungement paperwork for you, generally quite affordably.