TrafficDroid, now this thread has settled a bit I'm going to be a bit more serious - I am left genuinely concerned over a few issues with your safety.
Please can I try and offer some helpful advice? I don't want to come over as condescending, please don't take it that way.
The impression I'm left with is a feeling that you might benefit from assessing some of your own road technique and particularly life saver observations.
I don't claim to be an expert but I have had some advanced training in cars via previous employers and on motorcycles under my own steam.
I too spent a few years travelling for work through London (and other cities for work purposes, both in the UK and abroad). I've done this in cars, on motorcycles and whilst cycling. Landing in Rome and getting through the city late on a Friday night, on a motorbike or LHD car, being typical scenarios; thankfully these days I don't have to do it and if I can avoid rush hour(s) traffic, I'll engineer my trips accordingly.
The advanced motorcycle training was most useful, it was a long time ago admittedly (at the turn of the century) and things might have changed slightly but I imagine that some of the key drills are still going to be the same.
Defensive driving was key to this training - developing a mindset of avoiding putting yourself in a scenario as much as possible is the aim here.
One of the key factors in this approach is the over shoulder check; this gets drilled into you to such an extent it becomes engrained so that you do them when using all vehicles.
It is very useful for blind spot safety on motorways, junctions and roundabouts; it also applies to multi and single lane traffic use and is chiefly about avoiding being caught out by under-swipes (just like the one you have shown in your video) - it helps in many scenarios.
The checks apply to both shoulders when taught on a motor bike and can be transferred well onto other vehicles with a little thought, it's a practice that has saved me more than once whilst driving at home and abroad as it is so transferable - if I can suggest that you take away one thing from this thread, it is to find out about the technique and try and apply it to your cycling? If I push my luck and ask for one more thing, can I also ask you to do some further research into road positioning?
This will get you started:
http://www.begin-motorcycling.co.uk/elc3.htm