So a bumi buyer gets bumi discount, is the lot automatically called bumi lot?

I have a friend who bought with the discount, and is having a hard time trying to sell off now as the potential buyers are all non-bumi. He said according to the land office, he may have to 'return' the discount, but I have no idea how this can be done and to who.

I'm a bumi and didn't get any bumi discount for my two houses. So hopefully I won't encounter such problem if I want to sell one day.