I prefer prong collars to choke collars, only because the choke collars close completely which means the dog is at risk for strangulation. That being said, they can be a wonderful training aid, and I have seen them used safely and effectively on many dogs.
If you do not have the training or experience to use one correctly, I would recommend you simply tell the owner that you are not comfortable using the device as you are not familiar with it and don't want to accidentally harm the dog.
It's unprofessional to judge or condemn another owner's training methods unless they are not effective, or abusive, and the use of the choke collar doesn't fall into either of those categories.
Your information about causing hot spots is incorrect. Hot spots are caused by a wide variety of conditions, sometimes including genetic predisposition, and is not directly related to training methods.
Safety rule: NEVER allow a dog to wear a choke collar (or any training collar) around the house. He should have a separate collar to hold tags, and the choke collar does become a safety hazard if it is never removed from the dog's neck. It's a training device, not a necklace.
If you don't know how to use one properly, it can be bad. I personally prefer prong collars. Both the choke collar and prong are used to give a little 'tug' or 'poke' if the dog is not behaving, and it should literally be a one second 'tug' or 'poke', not a prolonged discomfort.
Exactly what Dorothy said. Use it as a training tool give them a little one second tug and then correct the behavior. But for big, strong, dogs that need to be trained choke collar is the way to go.
one dog walked over the other and got her foot in between the choke and the other dogs neck then they she flipped 2x and im watching the bigger dog dying because he couldn't breath. We managed to flip her back 2 x and finally we got them apart...yes a freak accident. And no choke chains are not good