I was the person who was knocked off on Thursday.
I was cycling down the cycleway in Green Park (I normally cycle down the road on Constitution Hill, but the lights were "in my favour" - famous last words - to cycle in the park on that day). I was overtaking another cyclist towards the end of the cycle lane opposite Buckingham Palace, and he abruptly - and without checking behind or indicating - turned right in front of me and knocked me off my bike.
I don't remember much, but I was knocked on the floor and sustained a nasty head injury that meant I lost a lot of blood. I've fractured my cheekbone in three places, and am left with a nicely blued right-side of my face and stitches.
Apparently the cyclist stopped briefly, and then cycled off - leaving me on the floor. I was very grateful to the pedestrians who stopped to help.