drink driving

What is it with the police that they don't believe me.

After a meal and a drink at the pub I was pulled over for a Random breath test.
So the officer asked me
Have you had any alcohol
Yes
How much
one drink
when
two minutes ago.

So I answered their questions. I was telling the truth and they wanted me to blow in the bag.
Don't they believe me?
Do they have no faith at all in the general public?

Obviously not. We are all liars, cheats and potential criminals.
I don't know about you, but I feel just a little offended at their total disregard for my honesty.
When the police do something wrong we are told not to tar them all with the same brush. Perhaps that homily works both ways.