Folks,
Lets not jump to conclusions. They may have had an oil leak, slow and figured they would not make it. They may have kept the thing running long enough to make a safe diversion to JFK. They may have had a vibe problem and pulled the power back to try and save it, still producing power, while they diverted. The list is endless!
WE do not casually shut down engines on a twin like we might on a 4 motored bird.