Sorry you took offense, but you pretty much answered your own issue when you said "most other ethical K9 handlers" and "ethical, responsible, and well seasoned dog handlers". Most - that means not ALL, correct? What about non-ethical, non-responsible and non-well seasoned handlers?
Just like in any other walk of life, there are good, ethical people, and there are unethical people. That goes for LE, lawyers, doctors, politicians, and certainly for dog handlers too.
We also do not know officially who the dog is, who the handler is, what relationship they have with LE. So there is no way to judge how ethical, responsible or well-seasoned they are.
And, I hate to say it, but that is such an EASY way to get probable cause that LE does it. In fact, I know about it because I was told about it in one of my classes (they were NOT suggesting that people do this, but they said that it is done.) I guarantee you that there are professional, paid handlers who would do that to help LE out.
Again, sorry to offend you. I know that there is a close-knit community of SARs (my brother is a SAR volunteer - not with dogs but with alpine rescues), but there are some less than stellar people in every area. You would not do it, but I am sure someone would.