The segment's online, this doesn't seem to be a review for comedic value: http://www.youtube.com/watch?v=8DfHyGD7_pM
Clarkson (the presenter) seems to have clarified what actually happened on the day here (2 pages, starts near bottom of 1st):
http://www.timesonline.co.uk/tol/driving/jeremy_clarkson/art...
There is an especially strong claim in the article:
Tesla could not complain about what was shown because it was there... Tesla, when contacted by reporters, gave its account of what happened and it was exactly the same as [Top Gear's]. It explained that the brakes had stopped working because of a blown fuse and didn’t question at all [Top Gear's] claim that the car would have run out of electricity after 55 miles.
So either Clarkson's grossly misrepresenting Tesla's behaviour so far, which would be very odd, or Tesla's suddenly done an about turn and thinks it can get the BBC to say something else.
But the BBC's not playing ball with Tesla at all: http://www.bbc.co.uk/newsbeat/12907367