I wonder if I actually know you and the user mknocker. Seriously, it's scary to read this stuff for how real it is :)
Anyway, a company who puts that person on the phone as one of the first points of contact has serious communication issues. It was an easy pass for me (I already work in a company with broken communication).
I also usually ask "if someone has left the company in the last year" or so. However, they might lie, but most of the time they are not prepared for such a question. Reading micro-expressions (I am trying to learn...!) and the tone of the voice might help you with that, so that you can dig in and put some pressure to get some truth out of it.