Having been a Home Depot employee, (yes, yes) I know that the company policy is to use only licensed and bonded installers for all company installations. I haven't seen the flyer for the free permit either, but I'll have to check it out.
I know that in the store that I worked in, we had three licensed electricians, including a master who was the department head for electrical. Two of the people in the plumbing department (including me) carried a plumbing license or a EPA cert or both.
Unfortunately, not everyone is safety minded, whether they hold a license or not. The Home Depot training is fairly good, actually.
As with anything a consumer can buy themselves, people will do just about anything after they leave the store.
I could probably start a whole board of horror stories, but...
