This one boggled my mind when I first heard it on NG because the change in the story happened within 20 seconds. There is a big difference to me between a couple of drinks and a beer. I'm thinking he threw back the former, but either way, quick change up on the story to minimize the drinking as Nancy kept pushing...
http://transcripts.cnn.com/TRANSCRIPTS/1101/12/ng.01.html
BILLIE DUNN: I know that there was a lot of food out,
and I think Shawn had some drinks. Nobody else. Nobody was worried about having a New Year`s Eve party.
GRACE: Did you have the TV on?
BILLIE DUNN: Yes.
GRACE: Were you watching the ball drop?
BILLIE DUNN: We were just watching news.
GRACE: Are you sure?
BILLIE DUNN: Yes.
GRACE: So you`re telling me that you have people over, you had food out, alcohol was being served, but it was not a party.
BILLIE DUNN: There was no party, and we weren`t serving alcohol.
I think Shawn had a beer.
GRACE: So it was just him.
BILLIE DUNN: Nobody was trying to have a party. that was -- right. That was on nobody`s mind.