sat here with the usual 20/20, why not attempt a return to 03, it would have saved a lot of time, I think eyeinthesky mentioned this as background, but was it an option? real emers are a little bit different to those in the sim. rip and condolences to the families
Probably not part of the decision process, but a right turn would take them back over Biggin Hill village, which is even more densely populated than where they went in.
Having said that, if, as I suspect, they took a decision a mile or two East of BIG, heading East at 2400' QNH, 1800' AGL, it would not have made a huge difference which way they turned, but the turn onto 210 is actually less than onto 030 and 21 was more "obvious" as it has an ILS and all the lighting, and was the active runway.
I would have turned left under all the circs.