I hope that my pup will always think that the whistle is a positive re-enforcement and not think "what the heck did I do wrong now" and dread hearing the whistle. I really hope that it can always be a that way. A feeling for the dog of I'm here to help out in the field.
It isn't always that way with my older dog, and it's my fault, my first dog.
A "sit-nick-sit" maybe too often, a 'burn" when not deserved, a "give my best buddy the benefit of a doubt" not often enough. All those things that over time maybe instill a negative reaction to a whistle.
Now I don't consider myself heavy-handed, just the opposite. But over time I think corrections when really not required or warranted may make a dog think of the whistle as a negative re-enforcement?
Do all dogs consider the "whistle" as a negative? It sure seems my young dog doesn't and is eager to stop and take a command. I hope it always is that way.