I can't find the link ATM but I read the other day that HMRC are being very agressive about recovering unpaid tax with a good deal of success.
Apart from legal fees, it will cost them nothing to test the 'Leeds' rule again. Legal judgement can change over time and they might be lucky this time.
However, I'm confident that there's a load of other ordure to come out and I'm sure they'll get PFC one way or another.