I don't think PC-ness enters into this.
In fact, its quite the opposite.
The original message (if you read it slowly) described people judged merely by `looking around the aircraft cabin' and deciding who was `British'.
Even listening to them talk wasn't mentioned.
Clearly that isn't workable, as described.
London's population itself is now 1/3rd `ethnic'.
Perhaps y'all just aren't aware of it,
but there is a background to this in that, unlike the 2-party system in the U.S.
where both adhere more or less to a written constitution,
in Britain there is a minor but active racist `British National Party' (BNP) which runs in elections, wins the odd town council seat, and uses any oppurtunity to classify `British' as white and English-speaking (the rest, even if born in Britain, `should be sent back where they came from').
Its the -opposite- of PC to say
`uh, you can say that, but you are wrong: here's why'.
There was nothing wrong in making sure Arsenal's opinion did not reflect or mean to encourage a BNP outlook, and I think he clarified or amplified his actual intent satisfactorily.
Mere curiousity on my part.
You can call that `PC police work' if you are of a paranoid persuasion, or a Rush Limbaugh dork. Its a free country, so I'm told.
` Yeaah! Baade 152! Trabi of the Sky! '