I think that what you mean is that once a FWD car is sideways beyond a certain point, that there is no saving it, but to be honsest, it's hard to get into that situation in a FWD car (for me) I mean, FWD oversteer can cause accidents but it's more the fact that when you are oversteering in a FWD car and you use the throttle to balance it, you end up on the other side of the track (effectively "changing lanes" so to speak), and on a street track, this would end in tears indeed.
To a degree, accelerating when oversteering is against most peoples instincts I guess, but like I said before, you can't 'forget' that you are in a FWD or RWD car, it doesn't make sense to me that a person could or would forget that. Every corner tells you that it's a RWD or FWD car, especially when applying the throttle on corner exit.
In a sense, FWD cars can snap quite unexpectidly mainly because of "lift-off" oversteer, rather than "power on" oversteer that RWD cars can suffer from and "power on" oversteer is more what a person would expect from a race car so in that sense I would agree that maybe the prediction of oversteer is harder in a FWD car than a RWD one.
As for an Eau Rouge situation, I think that it would be equally as difficult, if a FWD car oversteered going into there, the chances are, you're gonna end up in the wall. As for a RWD car, it could be very diffcult to not overcorrect, and to balance the throttle.
I don't think it's that good a save. All he did was go full-lock, it was luck and physics which righted the car. Sure, it was fun to watch and cool for him, but hardly a save that requires endless dissection.
He would have just put the clutch down so the wheels were free to rotate backwards without the engine stalling then grabbed a lower gear and got going again. Luck always plays a big part in these saves and he did get lucky but did very well at the same time