Not in a backhanded way, either. He also offers promotional advice for setting up the rematch with Holm. Rousey has been a vocal critic of Mayweather's domestic history causing some eyebrows to lift when she started dating alleged abuser (and married man) Travis Browne.
I think she'd be wise to just visit another elite boxer's camp is she wants to improve her hands. I also think that won't help her win vs a superior striker in Holm unless it's to concentrate on defense and how to get close enough for a throw. Even better, go to a better MMA camp to improve.
Mayweather and other athletes including Holm are coming to Rousey's defence recently on social media, where the blood is in the water of late. Frankly, don't talk shit if you don't want shit. Rousey talked a mountain of shit and now she's queen of it.