Miss W was arrested in central London during the early hours of the morning in mid-2016. She had failed a roadside breath test and was taken to a City of London police station where she was required to provide two evidential samples. Before a motorist provides such samples police have to check that during a period of 20 minutes prior thereto nothing has been eaten, drunk, consumed or “brought up from the stomach”. The police asked my client if she had brought anything up from her stomach and she responded by saying that she had. Despite this, police proceeded to take samples of breath from her straightaway and did not wait 20 minutes. The results were over the legal limit and she was charged with drink driving. A trial took place at Westminster magistrates court, and her defence was that the breath results were unreliable. Police have to wait 20 minutes because if something is brought up from the stomach it might contain alcohol which distorts the reading. Despite the police officer admitting that he did not wait 20 minutes, the magistrates rejected the arguments for reasons that were never entirely clear. I took the matter to appeal to Southwark Crown Court where a judge had little difficulty in ruling the samples must have been contaminated and her conviction was overturned.