Don't really agree with you there mate. It's not like he went specifically out of his way to mention it - it was an anecdote that popped into a conversation. Was he supposed to turn around and say "I've got a relevant anecdote about Michael Owen...oh, wait, I can't say that as it might offend Man Utd fans because it's the Munich anniversary tomorrow. I'll tell you my anecdote about bad turbulence on a plane ride next week". The plane ride wasn't even the central part of the anecdote, the anecdote was primarily about what an arrogant twat Michael Owen is.
I can agree with you, to an extent, about the double standards. But as I said in my post above, if Liverpool fans behaved this way if an ex Utd player made some anecdote with an oblique relevance to Hillsborough, I'd tell them to stop trying to manufacture offence as well.