Update 6-19-13: Lil Wayne released a statement yesterday on Facebook to explain/defend his actions:

Lil Wayne, facebook.com

Tunechi, Dwayne Carter, Lil Wayne... whatever name he currently uses, decided it would be a good idea to use the flag as a doormat during the shoot for his latest music video, "God Bless Amerika". The single is off Wayne's newest effort, "I Am Not A Human Being 2"

You can hear the song in it's entirety below.