While the following story didn't happen here in North Carolina and even though it's a bit older, it highlights a very critical point about breath tests when a person is accused of driving while intoxicated.
In 2012, a woman was pulled over and accused of drunk driving. When she was asked about taking a breath test, she responded with lines such as "do I have a choice?" and "I guess, yes. What am I gonna say?" Such ambiguous language, according to the police and the court, meant that the woman was refusing a breath test because the question the police asked her requires only a "yes" or "no" answer.
The woman appealed her breath test refusal charge, but lost because it was reiterated that her response to the question was ambiguous and failed to adhere to the "yes or no" basis of the conversation she had with the police officer.
Now, this all may seem silly, but it does highlight an important point about breath tests. The minutia of the rules involving breath tests is critical to the criminal case. It can help support the police's action, or it can support the defendant's appeal.
For example, there are very strict rules regarding the handling and application of a breath test. What if the police officer failed to perform these rules adequately? What if the officer's actions corrupted the test? These circumstances could lead to a successful appeal by the defendant. It may seem like a technicality -- and that's because it is. The police and the prosecution have to follow the rules, for if they don't, the case against a person being accused of a crime can be dismissed or tossed out.
Source: The Daily Journal, "Gloucester County woman loses breath test appeal," Jim Walsh, July 14, 2014