There was very little that caused Balthazar to stare in utter confusion. After all, he had seen some Things in his day (mostly the weird crap humans got up to). So someone downing a glass of wine as if they would die really shouldn't have caught his interest, but watching the reserved man (angel, whatever) next to him inhaling alcohol like that was almost cause for concern. If the idiot didn't pass out in the next 30 minutes from it, he'd have to give him a pat on the back.

Balthazar, on the other hand, was not about to down a glass of scotch for anything, thank you very much. "You're mad," he said to Aziraphale. "And you're juvenile," he pointed at Gabriel. "And I'm not going to destroy glasses where I work." Was supposed to work. Details. He tipped the glass to his lips and drank from it very slowly.