A verbal promise can very easily be interpreted as a contract by a court. (IANAL, and clearly YANAL)
The commenter hadn’t even done the interview yet. There’s no way a court would interpret this as a contract to pay the person that amount.
The legal side is almost irrelevant. The situation is that they're trying to initiate what should be a mutually-beneficial, longish-term working relationship. Leading into it with this kind of letdown isn't a good start.
The only reason it's not a contract is because the job offer wasn't closed yet. This is more similar to false advertising.