I was on for my second nuke on Afghan last night and died by a rolling semi random frag at 20+
best way to deal with that is semtex to the fuel tanks behind him through the skylight.
I had another Xbox here yesterday and that was amongst the things I did a little work on
With Semtex from the inside look up as far as you can go line up the throw through front middle pane. This lands in the middle of the occupiable area of the roof and works if the tank is blown. You can also do angles with the same alignment to hit either corner up there
To blow the tank move back one window.
From below outside tuck yourself into the corner formed between the side of the shiny metal rack and the windowed outside wall of the little shack turn so you back is against it look straight up again and throw towards the middle of the roof.
I've done it before with free throws, but that should sort it for good. SitRep also helps to make sure you get the tactical insertion as well. Danger Close Semtex should cover pretty much the whole roof with a middle throw.