I can't believe that. The UK Government website certainly doesn't control Thai Immigration rules but they do discuss requirements in detail with the Thai Government and print those requirements on the UK Government website. Wether or not immigration officials offer leniency is another matter. I just checked the Thai Embassy in Australia and that also says you need 6 months remaining on your passport. Its not an airline thing it's a Thai Government requirement.
BS. You said you cant use a re-re-entry permit on a single entry and you dont need one on a multiple entry and ended of say "so you are wrong on both counts"....... The tone was the same as your next reply....one of insecurity