When stating "was under the legal alcohol limit for aviation workers" it need to be remembered that the limit is not set to zero as it necessarily needs to make allowance for normal bodily functions (i.e. as is oft said, the human body itself can manufacture alcohol) and therein even a teetotaller could blow a 'non-zero' reading. It is therefore very unfortunate that this is not emphasised in subsequent reporting of 'not-guilty as below the limit'.
The limit for aviation is such that being under it you are effectively are as sober as a judge.