I read up on it too since I'm posting here and I'm not lazy. It's odd that despite your amazement you didn't bother to learn exactly what these animals are. It's pretty easy information to find.

In order to get them, you have to be under the ongoing care of a licensed mental health provider. That's not an inexpensive thing to do. It has to be ongoing care so it's not just a drop in thing. The professional's opinion also has to be that there's a valid reason for you to have the animal with you.

I've flowed 15k miles thus far this year. Throughout my life, probably a million. I've seen 1 dog non-tiny and in a carrier dog on an any flight. It happened to be an AS flight. Other than a police dog, I haven't see anything other than a purse dog on a flight. Didn't know it was there until we were deboarding.

While I'm not saying the OP is lying, I'm highly doubtful of the story. In the case that it is true, it's so remotely unlikely to happen to anyone here, I'm really not sure it's worth the 5 pages of mostly uninformed comments.