It's totally legal, in New York. I doubt that it covers interviewing expenses. I think it only covers stuff that happened after they signed the offer.

And I really don't appreciate being dinged for the actions of my corporation. I was not involved at all in that part of things, and only heard about it afterwards. I had many disagreements with our HR department, which could be rapacious. However, it was run by highly skilled and experienced lawyers, and everything they did was legal (if not always what I considered ethical; but I have high ethical standards).