It's a procedural thing. Some guys put the landing gear down at 2,000 ft, 1,500 ft, or a 1,000 ft. I am guessing the latter had the UK controller in a hissy. I wouldn't worry about it. On every transatlantic hop you have on average combined between Capt, F/O and IRO 75 years flying experience in the cockpit.
Don't be too hasty here. I have flown jump seat many times over the years and observed a wide variation in crew procedures during approach.
Perhaps the Captain was waiting for the last moment for gear extention? Ever watch the space shuttle land??? If the crew was indeed surprised by the go around command from the tower, they would have punched the TOGA button. But they didn't. They simply lowered the gear and proceeded to land.
Whatever the case might be, the crew darn well knew about the gear being up with the "Landing Configuration" warning going off in their ears...not to mention the pretty red lights on the glareshield and the red LDG GEAR message on the EICAS DU.
Perhaps a bit of sensationalizing by the media with the help of a jumpy air traffic controller????