My friend was taking off from MIA one day in one of our B727 aircraft with the FO flying and just before rotation the number 3 thrust reverser deployed one of it's clam shells with no reverser light indication. He took control when the FO lost directional control and used full left rudder to maintain heading with some left bank. Climb was severely restricted so he reduced #3 thrust lever and regained some performance and some directional control. He continued to idle and was able to make a very wide circuit to the right and return for landing. He was told by fire rescue that his right engine reverser top half was fully deployed.
He did a flawless job of handling a critical situation that none of his checklists addressed. The pilot flying should always make initial power changes because only he can feel what the power changes are doing to the control inputs required, especially the rudders.