May has stated on numerous occasions that we will fulfiil our financial obligations, neither May nor Davis has ever said we will pay them nothing. The only question Barnier has ever asked is 'How much are you going to pay'. With respect, either you can't read, don't listen or are being deliberately disingenuous. If I am incorrect then please put up a link showing May, Davis or any of our negotiating team saying we are not paying them anything, and I will offer you a profuse apology.
There is no dispute that Brown encouraged the sale of diesel cars, but the idea that this was against all the best advice available is laughable, as I've already pointed out with the total lack of concern over diesel in the 2010 LibDem manifesto. In fact Brown didn't go as far as many others in encouraging Diesel use, when I lived in France our neighbours thought I was mad to drive a petrol engined car, diesel was around 25% cheaper at the pumps. Brown ensured that diesel was always more expensive in England. Incidentally you could do with reading that piece you linked again, parts of it are incoherent, but it also states it was mainly the civil servants advising Brown not to publish that report. It's all completely trivial nonsense anyway, if Brown had backed off on the dash for diesel the eco-loons would have been in a frenzy. As it was they got their way and thousands died.