The Herc was on MRR and had descended to investigate the ship contact and had descended to pass astern. The SK was climbing away astern and they collided IMC. The Herc also had a party of RN down back on an experience flight.
IIRC not only did the lose the wing and have damage to the outer engine they also had to shut down the remaining engine on the same side.
After landing at MPA they put everyone on a wokka to take them back to Stanley - which itself declared an emergency and landed back a couple of minutes after take-off. After that they put everyone on a bus.
I, for my sins, was Ops 1 and SFSO at Stanley at the time.