Yes, still a fair challenge.

His leg wasn't broken and if you look, it is a fairly run-of-the-mill challenge.

Neither the FA nor even Arsene has really said anything bad about that challenge because there's nothing to say about it.

P.S. I agree completely that dangerous tackles should be red carded, never said otherwise. My point clearly was that Barton's tackle on Diaby was not dangerous, but expected.

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Added on February 8, 2011, 5:23 pm
Indeed. There's no real way to measure referree performance anyway. They're entitled to make as many mistakes as players do, in my mind.

It's just that sometimes these mistakes occur in prominent events (penalties etc.)

It was the linesman though, who gave the crappy second penalty.

This is just an argument for video technology, in my opinion.