IF you are correct and the BAC has to do with the bypass and you would not have been over the limit (anywhere over the limit: i.e. if you would have been over the limit anyway, even if by less, you'd still be liable, so just "reducing" the BAC doesn't necessarily help that much), you *may* be able to escape liability, but to do so, you would need a medical expert (i.e. a doctor with expertise in this area of medicine) to testify about this in court, at your trial, as to how the bypass affected your BAC and what it would be have been without the bypass. The case will not be dismissed ahead of time on your say-so, or even based on medical literature you might provide. Having such an expert examine you and testify can cost many hundred or several thousand dollars, so you would have to weigh carefully whether it is worthwhile trying this.