If the RB took the snap and stood back there trying to make a pass, then I would assume he's afforded the same invisible shield as a QB. However, once he takes off running, which is what they did, then he's fair game to be tackled like any player. Now it would be interesting if he took off running and just before being tackled he took a slide. Technically, that's be a penalty if he got hit, right?
But as for the QB out there, I'd say he's fair game. And I'd line some up against him and knock the ever lovin crap out of him. I heard one of the talking heads this weekend say they called that formation the "kill the QB" formation. Because if you ever saw it, you ran a LB over and took out the team's QB.