Well, I hope he isn't a captain with an attitude like that.
I do realise that this was an almost impossible question to answer, given that I simply can't give sufficiently precise details. I just wanted to get some ideas on what was flying over East London. Your answers and thoughts have really helped.
I too noticed the very low aircraft speeds on that website. They had me wondering "do commercial aircraft really slow that much on final?" There was a 747 landing at Heathrow at 108 knots, which seemed a tad slow, even to a PPL like myself.
Thanks all.