I'm sure that this is the case. While I don't think that this is a *cover up*, per se, it appears that the responsible parties are trying to handle the issue directly, rather than let it descend into a media circus.
Regardless of whether or not the Marines overreacted or are somehow at fault, the political situation is tense for Karzai and Bush. The fact that there was a suicide bombing will be totally overlooked, and the CSI wannabes at the networks will convict these guys for ratings. Pulling the unit out is a symbolic gesture, rather than simply relieving the local commander, which would be more functional. Given that fact, it would appear that, actual wrongdoing or not, some kind of deal was cut to remove the *guilty* party, in order to resolve political concerns.
I agree. Not a cover up. They are just trying to keep it from getting out of control. I hope they've taken the Marine Special Ops unit and quietly put them on another mission somewhere else in the world right away. Not that they are criminals but it would be something like the "Dirty Dozen," only in this case it would be the "Dirty 10 Dozen."
Otherwise, that's too many war fighters sitting in limbo.