The bollards may be quite a good marker. There are no bollards in the Q pic, so perhaps they original bollards that contributed to the fatality (5th March 2014) were removed in March 2014. However it appears that the new bollards were installed sometime in early May 2014 (SV images). That could potentially narrow things down quite a bit.
Not sure why I put early May there, could be anytime in May.
Anyway, one of the things that has bugged me since I started looking at the London pics was the little yellow sign(s). These appear to be warning of impending road closures (pic 2,3) - however May is too far into spring, too many leaves on the trees. Also even though they are potentially unrelated, the shroud was also up on the Cov st building in May. Similar signs were up before and during the London Marathon 2014 (April 13th 2014) and the shroud on part of the Palace of Westminster was up. I appreciate that this is a bit of a rambling post - however there is something there though (I think).
Moon anon maybe worth looking at April.
There are also quite a few youtube vids showing the marathon, but annoyingly they are either low res or don't show the correct areas.
Also interestingly, the bit of the course that is the ROT set is the 25 mile mark of the marathon.
> April 1
Now this is just unsubstantiated wild speculation but I had wondered about Apr 1, April fools day. These people are stupid.
Shroud pic. Feb 2014
https://www.youtube.com/watch?v=HEbEdC2D6Y8