Whilst in the RHS i did once take over in the flare. Capt had just changed types and was very new on the aircraft. Landing into XXX after a very busy app. he had memory lock and treated it like his old mount. Chopping the power at 50ft rad alt, hauling back on the yolk and then waiting for the main gear to touch... oh dear. Sir Issac Newton took over and...
I said I have control, gave it full throttle, and pitched down to stop the tail hitting the hard stuff first. No time to go around, just did what I could to keep the plane in one piece. We hit fairly hard still, but no harm done to the A/C, had a heavy landing check there and then.
The Capt, to his credit thanked me as soon as we came onto the gate.
Don't get me wrong, I'm not saying its the thing to do by any means but every now and then, when the situation dictates, someones got to prevent a bump...