While we worry about how and whether to write about tricky issues of metaethics for the folk in the public square, some people have a much bigger problem.
E.g., if you're a Muslim in London you may find a lot of grief if you want to give a lecture to your co-religionists on the topic of "Islam and the theory of evolution" ... in which you plan to teach well-established science. You might find yourself getting outraged responses from members of your community, including what Chris Mooney would call "even, apparently, some death threats." You might, to put it another way, need to deal with a style of incivility seldom displayed by liberal atheists.
If so, perhaps you'd be wise to cancel the lecture and issue a public recantation of your "errors" - right? That's what Usama Hasan did, and I'm not going to blame him for doing what seemed needed to save his skin.
Look, I'm not an Islam basher, unless you count my sceptical attitude to religion in general ... and my denial of its authority.
I don't want to conceive of Islam as simply an enemy to be opposed by all possible means. It remains my hope that Islam can reform and adapt to secular modernity. It may be that not just some but most Muslims living in Western democracies have already embraced much in the way of liberal ideas (though it would be nice if they'd raise their voices and say so). But this kind of thing doesn't exactly give more hope. Where is the outrage from within the Muslim community that Dr. Hasan has been silenced and intimidated into a public recantation? Will we hear prominent Muslims condemning this? Will I be accused of "Islamophobia" for commenting on it?