Definately sounds like a miss-quote. Without the X/LON I'd wager they've charged the UK APD for Business Class of GBP146. Should be fairly easy to sort, via ECH, with a reissue and part tax refund.

Those DONE5 (Round the world, Global Explorer's) don't quote automatically in Amadeus (i believe) so it always has to be a manual fare recalc, giving the opportunity for errors to happen.