Red bus in black&white with overcast sky?
Give me a break... what are the chances to shoot with an overcast sky in London?
Besides, isolating a (mostly) single color object in a B&W photo is so popular (and abused) that you can even have it in new point&shoot cameras.
Go, figure: http://www.dpreview.com/reviews/sonynex5n/page10.asp search for "Partial Color (R)" and click on the link.
Seems quite obvious that if you find yourself in that photo spot, and a red bus passes by, you immediately think to make it pop out with such a post processing trick.
I also don't buy the "clearly produced with the intent to evoke the same expression" argument. For example: how many pictures of the Matterhorn (with or without the lake in the composition) are taken and evoking the same expression?
This is simply a very bad judgement.
(Just to be clear: I see your point and my tone is not directed at you)