If the duct tape was applied to a live child and some hairs were pulled out in the process wouldn't those hairs NOT have the "deathband" of a post mortem hair? If it also had hairs that DID have the "deathband" hair I would think that could prove it was applied to a live child who died after the duct tape was in place.
This is an excellent observation. Those hairs very likely could tell the tale of how it played out.