As much as I respect your insight, I really dont think the duct tape is a serious issue. I just took a 360 degree close examination of his hide, and I found only about 2 millimeters of open sticky-side duct tape on it which I snipped off. Even if he intentionally tried to stick himself to it and pull the duct tape off, he really couldn't. He just goes around touching things with his nose; even if I held a strip of duct tape in front of him he would probably just touch it and back off : / I really dont think he could peel the duct tape off of the box, as he has no fingers or anything of the such to do so.
Plus, even if he somehow managed to rip some of the duct tape off, the sticky side wouldn't be sticky anymore because it would rip off the carboard if it was removed.
P.S. My snakes hide is an inverted top ramen box with a hole cut in one side + other cardboard taped onto the sides. ( I've been changing his hide alot to try to keep as most light as possible out. )