Jay-Z takes Subliminal Shot at 50 Cent on "Watch the Throne"

Looks like the shots between 50 Cent & Jay-Z haven't slowed down. On the track "Murder of Excellence" off Jay-Z and Kanye West's most recent effort Watch the Throne, Jay-Z claims...

If you put crabs in a barrel to ensure your survival
you gon' end up pullin' down niggas that look just like you
What up Blood? What up Cuz? it's all black, I love us

Jay-Z rarely takes direct shots at artists, always opting to be indirect and never saying an artist's name. He is also very precise with his word usage, and in that way always makes it very evident his words are subliminal shots. Will 50 Cent take the bait and respond, continuing the back and forth? Or will he let the potshot slide?