Once I took control from a Captain as a junior FO. I took control too late and the situation was a ball ache to sort out (pointing at the ground 2000', flaps 3, TOGA thrust) after a go around done in a piss-poor manner. I sorted it out, but I must say it took me too much time giving verbal advice then instruction before I took control. It isn't an easy thing to do, especially as a very junior FO flying with a senior training captain.
I handed the aircraft back to the captain downwind after he regained his spatial awareness.
I wasn't for a second thinking about legal bollocks, only the safety of the aircraft.
The company view was I did well, but my mistake was to take control too late. Easy to say in the office with the FDM data infront of you and time to think.