Breathalyzers aren't 100 percent accurate, so there is a possibility that you can question the results if you've been accused of drunk driving. Breath tests have to be calibrated correctly and given by trained professionals. In addition to this, those giving a breath sample could receive a false positive if they burp or recently had a drink of alcohol that is still present in the mouth's tissues.
Breath tests are a good indicator of whether or not someone has been drinking, but they're not the solid proof they're presented as. Breath tests have the potential to be inaccurate. For instance, a breath test might read .07 percent on the person's first blow but .4 on the second. If the test is off by more than .02 percent when given consecutively, then there is a problem with its calibration and it's likely to be poor evidence that may not be used in court.
When you're accused of a DUI, working with someone experienced in DUI defense is a good idea. Challenging a breath test's results is just a single way to address a possible charge. Another thing you can do is question the training of the officer who gave it or seek to have the so-called evidence thrown out because of a traffic stop that was not legal.
There are many ways to help people accused of DUIs, and not all of them require admitting to guilt or taking alternative penalties. Our site has more information on criminal defense and what you can do to defend yourself if you're accused of drinking and driving.