Internal Possession in New Hampshire

I was arrested after coming out of a house party that had been broken up. My friend and I (both 18) walked past a few police cars in the driveway with no questions or hassle. We had not been drinking that heavily (2 cups of beer each). We were safe to walk home, we were speaking normally, walking normally, etc. (I later blew a .1) and there was absolutely no signs of public intoxication. We were walking down the driveway when another police car was turning in, I said "another f----ing cop?!" Apparently she had her windows down (4am in November), and heard me. Stupid of me, I know.

She immediately SLAMS on the breaks, jumps out of the car and yells "hey, hey." She takes both of our IDs (no previous record) then asks if we've been drinking. We both respond yes and she asks us if we have anything on us. Neither of us did, so we responded no. My friend talks more than I do, and it was obvious once having spoken with us for about 5 minutes, that we had been drinking. The officer arrests me and leaves my friend to go home. I went to the station and blew a .1.

My concern with the legality of this is:
- she had no probable cause to stop me in the first place (I don't think?!) she was just pissed that I said that (understandable yes, but still no grounds to arrest me)
- it was VERY obvious that she would have never questioned our sobriety if I hadn't opened my mouth, we were NOT publicly intoxicated.
- My friend was equally if not MORE intoxicated than I was and received no punishment

The offer stopped and asked you if you had been drinking. You were not under arrest at that point in time. You said "Yes". What more do you believe the officer needed to form a reasonable suspicion that you had been drinking?

Your friend apparently was an adult.

I can assure you that if you blew a .1, the only person that didn't think you were drunk was you.