The man staggered back, hand pressed to his rapidly blackening eye. "What the hell was that for?" he slurred.
"Ye're Douglas [lastname], aye?"
"Then be glad I dinna do more. It's only that she's chosen you that stays my hand. Take care of her, aye, and see ye do her nay harm, or by God and all that is Holy—"
"Wait." [lastname] held up an unsteady hand. "Take care of who?"
"Elspeth," he said. "My wife."
With the perfect focus occasionally allowed drunk persons, [lastname] studied Alec's face and proclaimed, "You are Scottish."
"Aye, and how has that to do with anythin'?"
[lastname] tilted his head and frowned. "Are you…Alec?"
"So my friends call me." Emphasis was placed on the word friends. "I am Alasdair Colin MacGreg—oof!" His words were cut off as [lastname]'s fist impacted his midsection, causing him to release his hold. [His hold on what?] This one was remarkably fast for a drunk man.
"You're supposed to be dead!" [lastname] backed away, shaking his head and dropping his voice. "She told me you were dead." [Thus I am justified in punching you in the gut.]
The dialogue is fine. Not sure about the POV. This one was remarkably fast for a drunk man is clearly Alec's POV. Whether Alec should be able to declare that Douglas has perfect focus is questionable. Also, try to think of an actual last name for [lastname], as it gets annoying this way.