I too have had the same experience. My AH told me he went to bars with his friends and drank soda and had just as good a time as if he had been drinking alcohol. Then it progressed to, " I had only two then changed to Dr. Pepper."
In reality the drinking never stopped. Testing himself was an excuse to be in the bar.
And yes, it's my fault he hid it and my fault he drinks in the first place, along with the old boss, the ex-girlfriend, his family, etc.
He knows I dont trust him, have caught him in numerous lies and his answer to that is, "Well you think i'm doing it so I may as well go ahead and drink"
The excuses are numerous. The outcome is always the same...they will continue to do what they do until they decide to change it. All we can do is work at our responses and at the end of the day, try to reassure ourselves that we did the best we could.