does he have the separate 16g sd card or is that the internal sd? the d3 has two sd cards. if he didnt get a sepearate external, just pop that bad boy in there. the slots under the battery cover, next to the sim card. hmmm.. or maybe if you have the external, take the 16g card out of the phone, and hook it up to w/e you used to transfer the data to the comp and move that way? does it say a particular file is protected , whats the exact message you get when you try to move the files?
i suppose you can also try putting the sd card in the phone, using Files (it came with the phone) to move the files from the 2g (/sdcard-ext) to the internal sd (/sdcard), poppin the 16 gig external sd card in, and moving the files back to /sdcard-ext.
good luck and i hope maybe someone else can chime in
ps: the 'external' sd card is actually inside the phone, and the internal one cant be physically accessed