I would suggest it was the 737 had a close call with a drone - the 737 was, presumably, in it's assigned airspace.
That said, is there room for some scepticism here? At 10,000 ft, the 737 presumably wasn't on an assigned approach to Stanstead (or any other nearby airport?) and flying fast > 250mph?
Very few drones I've ever heard of can even dream of that altitude and those certainly not capable of significant horizontal speeds. Nor could they maintain that altitude for more than bare minutes.
Is it common for pilots to actually see a single bird before the a strike? I ask (as a non pilot), recalling an in-flght visit to the cockpit of a 747 (decades back when it was allowed) and on seeing both pilots and engineer twisted in their seats to chat with each other and I - I asked why no one looked out the windows. The reply was, "No point. Even if we see something at these closing speeds, there would be no time to react". They were referring to something the size of another aircraft.
Really, can pilots see and correctly identify a 1 meter object in those conditions?