So in your opinion, if a movie needs to have a tall, skinny red head, and then they approach someone who has those qualities and the role is turned down, then it would be illegal to get any other different tall skinny red head.
That sounds absurd to me. If you have a role, obviously the role has qualities and requirements.
And just because person 1 who happens to have those qualities turns you down, it is still valid to get a different person who fulfils your original requirements.