Same thing happened to me once...about 15 years ago. Only instead of dismissing the charges they changed it to “wreckless driving”. My lawyer said there was nothing he could do.
I went through the whole process without an attorney but an attorney did tell me it didn’t sound like they were going to produce any evidence so I called the prosecutor’s bluff. By my 5th court appearence I think the judge was more than a little irritated with the prosecutor so he knew better than try to charge me with something else.