Buy out offer

System

I have a friend that has been offered a buy out along with about 30-40 other employees over the age of 55 at her company. She has signed the paperwork to take the buy-out, but the company has now come back to her and said that since they have gotten one person out of her department, the buy-out is no longer offered to her. I have never heard of such a thing, but she tells me that they have it on the contract how many from each department they want. It has been my understanding that if it was offered to one person in a company that it had to be offered to all, no exceptions. Do any of you know much about this. I offered it only once working through attorney's, but I'm not familiar enough with buyouts to give her much help.

Thanks