Dear Fredericksburg - While it is not fair - you will have a difficult time proving that the officer did not wait 20 minutes! He has control of the room and he writes the report of what happened. You should focus on the practical aspects of your case and working with your attorney to show why you should get the lowest possible punishment. Good luck.
Your attorney can find out if there is video in the examining room by making some phone calls to the detention center or even speaking to the prosecutor (as possible exculpatory evidence). Some lawyers have been successful in obtaining video (via subpoena) to contradict officer's testimony that he/she complied with observation period. If there is video, your attorney must act quickly to at the very least put the jail on notice that it will be needed for trial, so it is not erased.
Your attorney will need to do some investigation to determine if there is video in the room where you were waiting. He may also be able to talk to the police officer on the court date or by sending a request for exculpatory evidence to the prosecutor. Many officers and/or breath techs take notes of the time when they instruct someone to begin the wait period and you obviously have the time of the test on your certificate of analysis. If the officer does not have any notes then your attorney can cross examine him on how he is certain you waiting 20 minutes.
Among the things to discuss with your lawyer is whether the cop told you not to burp, and whether you told the cop you burped. All the best to you. Jon
None of my comments on AVVO's website constitute legal advice. It is only food for thought for matters to address with a qualified laywer. My website's disclaimer page at http://katzjustice.com/disclaimer.htm applies to all my answers on AVVO.com .