I believe it won't make a noticeable performance difference. But I would definitely want it lined up nice and symmetrical for aesthetic reasons.
I would take it back and ask if he'd fix it. If not, or is he gives you a hassle, I wouldn't do business with him again.
I asked opinions on a local Smith, if I should do future business with him because I caught him in a lie. The consensus was, "walk away". I'd only bought a single part, and I felt I got a good price, so i decided to give him another shot. Well... I lost my mag release retainer, and when he tried to bend me over for 20 bucks on a new one, that was all the further convincing I needed.
A good Smith is hard to come by. Bad ones are a dime a dozen it seems. Ask him to make it right.