I had a couple rejects due to copyright issue too, which I found
justifably prudent to err on the safe side.
IS has an office in Canada, which is quite
strict about copyright issues, our latest headlines being a massive charge on piracy of materials from the web. I guess that could explain IS strictness, but 123RF I am not sure. My only guess is that maybe 123RF reckons the wrapper is pretty identifiable as belonging to the maker of pharmaceuticals. Just guessing, though!