Sid,
Forgive me, but one point to factor in might be that the most clear-cut and effective assault on the Mirror's protestations would be to demonstrate that the pictures were taken somewhere other than Iraq.
If taken in (say) Preston, the case that the photos displayed abuse of an Iraqi prisoner becomes, shall we say, a little tenuous?
The other inconsistencies are neither here nor there once that key fact is established.
Pictures not taken in Iraq, ergo, they're fakes. No further elaboration or dissection required.
Of course, I could be wrong, but I think it is worth considering that possibility.