I don't see Rihanna having a breakdown. Chris beating her up made her a stronger woman so I doubt she's going to have one.
Plus, the people you expect to get a breakdown or get arrested usually don't.
Take Britney, Xtina & P!nk for example. You would think that P!nk would be the one who would get arrested or have a breakdown...but it ended up being Britney & Xtina while P!nk hasn't had any incidents.
So to everyone saying Rihanna, I disagree because I just expect the unexpected.