it's the UK Goverments website so I would think it's correct but irrespective of that, I am more concerned with being able to board the aircraft in the first place, it only needs a "different" interpretation of the rules by some jobsworth to deny me boarding.
I am sure many people have been allowed to fly and clear immigration with less than 6 months but knowing my luck, I'll be the one they make an example of so why take the risk ?