Great job Sparks! I know Colerain well as I used to work at one of those large shopping areas in Colerain. I too am glad you were with the wife and would encourage her not to shop alone after dark in that neck of the woods. It seems to be getting worse there.
Forget all the second guessing here, your awareness, and most remarkably your wife's, was great. You reacted reasonably and intelligently, letting the would be BG know you were not going to be his next victim.