Bill Clinton was the first prez to do it when he went after Tyson Chicken. In that case a couple of local plant managers were convicted but everybody at corporate level escaped.
GW Bush got convictions against IFCO Pallet company and a couple of smaller companies.
Usually they go with a civil prosecution because that is much easier and cheaper to convict. And, with a civil prosecution they can back off of the case if it isn't looking good and switch to administrative fines.
Usually the defendant will quickly agree to administrative fines because he doesn't have to admit to guilt and the administrative fines are less than the cost of hiring a lawyer.
No cost is too high to set an example. These execs should be doing the frog march. One or two high publicity cases would turn this whole thing around.