Sadly, it cost the MoD money.... they lost the case and had to pay about £1900 costs, IIRC. The judge agreed that the roundel had been in general public use, etc, etc.
Of course, the answer is for the RAF to change the roundel - just go to the Type B (that is the one without the white, isn't it?), along the lines of Arsenal FC altering the design of their cannon slightly, and copyrighting that.
Can I claim the £3,000,000 design consultancy fee that it would/will cost the MoD to employ someone to spend eight months to come up with that idea??