Look, I am going to leave this alone, before I am labeled a troll, but just tell me this:
Nobody here has a problem with Rea "appreciating" MC telling her the truth, saying people don't do that for her kind. Then turns around and tells you it is best to lie to someone else, till we can trust them? If no one has a problem with this accept me, then I am truly alone. And I will leave this alone.
I doubt anyone would call you a troll for that, I think you're good.
As for your point, I'm not sure which scene you're talking about so I'm missing out on the context, but the short of it is that you can appreciate (naive) honesty while not being (naively) honest yourself (parentheses are in case it's the scene I'm thinking of, we're talking really early on?).
It's just an unfortunate fact of life that sometimes it is prudent to withhold information, or even outright lie so as to not be taken advantage of. Let's say a young woman is alone at a bar and right before the bar closes a man approaches her. He's attractive, and seemingly being perfectly open and sincere and even seems pleasant as he goes "Hey, I saw you from across the bar and, I'mma be honest, was kinda looking to hook up, thought maybe you'd be interested?", raising a quizzical brow. Now, while he is being perfectly honest - which one generally appreciates - it's probably prudent to just tell the guy you're waiting for your friend in the bathroom, or something along those lines. Guy gets let down easy, and the young woman is probably that much safer until the taxi arrives, or something along those lines.
Rae is alone, and she is trapped with a stranger, and personally I just can't fault her for not divulging all the information.
Oh, and yes, the whole 'racial persecution' is a pretty compelling argument.