What breed was the other dog if you don't mind my asking. It may have been a breed which normally does not get along with other dogs and the owner was worried about that?
Off topic, but how old is your corgi and when do you plan on getting another puppy. Most people suggest that the best time to add another dog is when the first is around 2 years old (or old enough to be completely settled and grown), just something to think about
Lauren