Well, have you thought about this: "It is not the tape that matters, but the person behind the tape..." Sounds familiar??
Think of what the technician could have for lunch earlier: a delicious, drippingly juicy and greasy burger... "Oh, breaktime's up! I better go fix that broken wing panel..."
Scary isn't it?
Let's just say that every industry has its own dark secrets, a technician with greasy fingers applying duct tape on top a minor incident of cosmetic and localised non-structural defect is among one of the absolute last things that I would be worried about.