I've watched quite a few videos of dog's being sent for a retrieve and even though the dog is coming back there is a lot of recall whistle. As the dog is already returning what's the point, I have the whistle ready incase the dog veers off in a different direction or something distracts it otherwise I can't understand why. 

your dog might well be in a maize field and dis-orintated.......also there will be other dogs picking up as well..........if you are in the open and the dog is on its own ..then dont use it

only as and when............

I agree with you if the dog is in heavy cover or a bit confused if there's other dog's and people about but in lots of videos it's one dog in open ground I can only assume it's lack of confidence. 

It’s handlers who can’t leave the whistle hanging around their neck! Only time I do this is to encourage a young dog perhaps over an obstacle such as a burn, or if there are other distractions such as unpicked birds to run past/ignore.

I think that people get into a habit, they do it before the dog knows properly, do it to try and speed the dog up when young etc, then end up doing it hundreds / thousands of times and it becomes habit. 
 

If you asked them “why are you blowing the recall when the dogs already on the way back?” I bet they’d scratch their head or wouldn’t even consider they were doing it. 

I only carry on with recall if either I can't see the dog or he can't see me. Lovely example last week when one of the dogs was in high cover crop and had no idea where I was. 

always use hand signals when using the whistle.........cause some dogs go deaf very suddenly....(belive me i know)...i dont mean selective deafness...

14 hours ago, ditchman said:

always use hand signals when using the whistle.........cause some dogs go deaf very suddenly....(belive me i know)...i dont mean selective deafness...

Agreed. My oldest is working at 10 1/2 and is deaf but hand signals get his attention!