I remember years ago a batch of Schumacher Green's that came out a lot harder then they should have been but i don't think anything was done with it.....
Also last year i had a set of Green Ballistic rears and they were more like Blues, but that's going back almost a year now so is there a chance that the actual Manufacturer of the tyres may have changed the Green compound or something?
To anyone that doesn't race (incl Judges in Court, Manufacturer of tyres) they probably wouldn't believe it makes any sort of difference on an R/C Car as much as we all know it does so it would be a really hard thing to prove - Not every packet of Cheese and onion crisps will taste EXACTLY the same so that's probably the same arguement you'd come up against with Tyres......