H&M responded with this: "(T)he entitlement to copyright protection is a privilege under federal law that does not extend to illegally created works", graffiti in itself being illegal ergo it is not protected under copyright laws. Of course, this puts in danger the artistic validity of a graffiti artwork, it allows corporations to use the graffiti without going back to the original artist, and without any valid "collaborative" effect which would help the artist financially.
Unfortunately, H&M is right!
Never mind the consequences on the legal angle, but they are right - graffiti is illegal, which means that these artworks were done without permission, and therefore are put there for the enjoyment of the public. Claiming them legal devoids them of any "graffiti" attribution.
So maybe Revok should have thought of this prior of accusing H&M of violating his "copyright".
A perplexing situation indeed, but H&M is right.