That’s more than a riddle - it’s a really interesting thing to learn. I confess to a little skepticism though. I would think dogs are sensitive as much to the identity of their owner as to the words being spoken?
Already answered, but even without the dogs, it makes perfect sense that a manual would contain some such instructions. The police doubtless have not-infrequent occasion to give instructions to suspects who do not share a common language with any of the officers on the scene, and so it would be quite reasonable for them to have a phrasebook with some of the more common such instructions. The need for such a phrasebook would be all the greater for a language spoken by none of the officers.
On the matter of commands given to police dogs, they need not even be in a language at all. Horses are traditionally given the commands “gee” and “haw”, instead of “right” and “left”, so as to not confuse the horse with unrelated conversation.
I don’t know and I wonder if it depends on the sort of training the dog goes through. I imagine police dogs are trained very firmly to respond only to select people.
But it seems to me that the phonemes “gee” and “haw” are probably just as common in conversation a “left” and “right”?
You had too much fun with this.
I’ll add one, this one also googleable. Please don’t spoil for those who are trying to solve! 
The music stopped and then she died. Why?
I believe some heard this with alternate solutions, but I have a specific one in mind, the original I heard in the late 80’s.
Is “she” human?
Is it significant that she is female?
Is the “she” a (formerly) living human person?
Does “died” refer to a cessation of biological processes?
Was the stopping of the music the cause of her death?
Did the stopping of the music share a common cause with her death?
This one sounds really familiar, but I can’t remember the solution.
She was an opera singer.
- Yes.
- No.
- Yes.
- Yes.
- Yes.
- No.
No.
Because the radio fell in the bathtub she was in.
No.
Is she a specific historical figure, i.e. are we talking about a well known historical event?
No.
Does the music stopping/death have anything to do with loss of electric power?
Russian roulette musical chairs?
Just a note that i love these. I do specifically recall the answer to this one. So i won’t answer.
Unsure, but possibly.
No.
I do love these as well and it is fun to answer ones and give ones with a fresh group.
So, to be clear, the music stopping is the direct cause of her death, right?
Yes.