Maybe there is something to this story as ridiculous as it sounds. According to this news story...
http://news.bbc.co.uk/sport2/hi/motorsport/formula_one/6264904.stm
...McLaren may now involved and a memeber of there team appears to be on 'Gardening leave' after receiving a package of technical information from Ferrari.
I can't imagine why someone would do this unless there was large sums of money involved, which is quite possible but difficlut to explain without some fairly high level knowledge. As someone mentioned before F1 is a fairly tight knit community and everybody knows somebody. This sort of skulduggery wouldn't stay secret for long at the best of times and is sure to finish off a career.
The only thing I can think of short of a major lapse of judgement is that Mr Stepney has been stiched up good and proper.