You said earlier,
“Now that second whistle had obviously been paired with a strong correction in training and the net result was that got the cast.”
I think that your use of “obviously” implies that you believe the whistles were paired with strong corrections. Since I have seen the same reactions in non- collar trained or low nick trained dogs, I was suggesting that we couldn’t assume that strong corrections occurred in training. Now you are assuming that because some dogs vocalized after the whistle, it is further evidence of a strong correction in training. Did you ever train with any of those "Red Devil" Goldens in the past? Some of them vocalized on the sit whistle after the smallest and eevn rare correction!" I'm not saying it was happenstance either -I just can't assume I understand what happened in training by watching a dog at a trial.
However, let’s “ass-u-me?” you are correct. Then, using the whistle to help make the dog think about a strong correction is called a “conditioned aversive stimulus”. If you always use the whistle to associate with pain then you could argue it was a conditioned reinforcer which is also sometimes called a secondary reinforcer. Certainly if you "burn first and then blow the whistle" this could be the case! So if you want to label whistles as secondary reinforcers, it could be.- I won’t argue with anyone if that is how they use the whistle. I personally try to use the “sit” whistle primarily more as a communicating device to say, “sit down and let’s talk”. I hope my dogs don’t think they will get burned everytime they hear the whistle!
When we start to fiddle around with repeating stimuli such as whistles and nicks, we move into a whole branch of behavioural science that has to do with reinforcement schedules- ratio schedules, fixed intervals, variable intervals and more!. Frankly I don’t want to go there. You’re all welcome to look it all up. While we change our reinforcement schedules all the time, I haven’t found that studying and labelling all the schedules and being rigorous about them has helped my training that much.