The army often just can't tell who the Taliban are, and whoever dreamed up these hare-brained interviews must not have seen the extensive media coverage of "collateral damage" in 2012.
As far as I understand from the context, the journalist uses "must" as if s/he is pretty certain that those who dreamed up have not seen the extensive media coverage of "collateral damage" in 2012. (Sorry for the terrible wording!)
Is it common to use "must" in this way? Is there an alternative form to express the same meaning, perhaps using "might"?