Tasteless or not, of all the jokes that have been made at these things (think Ricky Gervais), this was pretty light. And the fact that it still prompted Smith to "defend his wife's honor" in this way? After everything she's done to insult his? Oof. I pity the man. He's obviously in pain, but Rock isn't the one hurting him and I don't know if he realizes. Maybe part of him does and that's why he seems so mixed up these days.
Kudos to Rock for being the only one to act like an adult and maintain professionalism in that scene. The transition into his next bit was awkward, sure, but how could it not have been? He was just as dumbfounded as the rest of us.