After reading your initial post again, I see now what you are saying. In your example, my concern would be more when the dog breaks on "careful." That seems to be where there would be risk especially if you're using a nick to try to correct this. Personally, I don't like to talk this much with the dog on point. I prefer to let the bird teach the dog that creeping isn't allowed. Once the bird is flightbound, I don't have to worry as much about the dog blinking when corrected. If the dog continues to creep, it's a good sign that more yardwork is needed.

That said, I have had to nick a dog to prevent it from creeping; but as I said earlier this was a very last resort with a dog that has the amount of drive and desire that there would be little risk in getting the dog to blink.