This was how it played out in the hearing. To challenge it further the way you suggest, and try to challenge the state cop's credibility, I would have had to take it to trial. That would have been $3500 in legal fees, with no guarantee of winning of course. It's not uncommon (in NJ, at least) for courts to rely on the officer's field observation when a breathalyzer test is ruled inadmissible. Especially, in my case, there were 3 officers on the scene so they could have all been called in as witnesses. I would have a very slim chance of holding up against the testimony of 3 decorated state troopers in a jury trial.
My lawyer was very familiar with the court, the judge, the prosecutor and how cases tend to go. He could have encouraged me to go further and take it to trial if he really felt we had good shot at winning and that would have been $3500 more in his pocket. So, faced with spending the additional money and <unpaid> time off of work to deal with more court dates, I opted to just take the medicine and get it over with. The 3 months of no driving were challenging, but went by quick enough that I can put it all behind me rather than agonizing over a court trial.