Actually I heard it live on radio and knew it was a joke. I think he saw a google alert come through and began talking about it, then had to think on his feet when he realised it was a mistake. Hence the kark joke!
I couldnt stand the UK broadcast either when I was there - very biased and the entire show is a dedication to British drivers. Annoyed the carp out of me. Remember too, that the facts and figures that Sasha uses come from a research department, not just from him - he may be the front-man who takes the flak, but mistakes are not his alone. In fact I have witnessed him correcting written stats that he received with accuracy.
OK, maybe I am a little biased and therefore defensive of the guy, but I still reckon he does a better job than anyone else I can think of to do the show.
I also heard about it on the radio. But a lot of his news comments have been inaccurate in the past.