It is left as an exercise for the reader to show how to determine whether the other publisher actually does have a copy, or is indulging in similar behaviour.
This reminds me of a similarly unethical behaviour I've encountered recently: I tried to buy a certain rare electronics component, and found it listed by a bunch of people. There were lots of bait-and-switchers in the Google results, who only had the part listed for the googlebot to pick up, but as soon as I actually tried to order the part, their site told me they didn't actually have it and suggested I buy something else from them.
It gets worse: When I finally did find a seller who allowed me to order the part, they accepted my order -- and then came back later saying that, oh no, actually they didn't have it either, but would I like to convert my order into an order for something else? (Fuck off.)
