Naturally, if normal directional control, in accordance with the flight manual, is working, use it.
But if you are out of control, and normal directional control is not working, you have to be able to at least consider the use of assymetric thrust. reverse or otherwise.
I recall the explanation for the information about not using assymetric reverse thrust from our director of training. Quite simply, if you are not good at it, it won't go well. There is a real "TOUCH" to using thrust reverse. The idea of thinking of it like the reins of a horse is excellent. But if you are not adapt at it, you will make things worse. So think about it, try it in the sim, get your mind working on the REIN thing and you will have an additional tool to keep your plane safe.
I DO WONDER which pilot was flying? Quite frankly, if you are right handed, it is easier to use the throttles, reverse levers with the right hand (as if you are captain), than using your left hand,(as if you are copilot)
IF I had to bet, I would bet the copilot was flying. But if anyone knows who was really flying I would be interested in finding out.