Agent Ray says to Henry, "I can still smell the hydrogen peroxide on your face." Hydrogen peroxide is an odourless compound, which breaks down into oxygen and water: both odourless. Agent Ray would not be able to smell any trace of the peroxide.
Grandpa is driving the Ice Cream truck and hears a police dispatch, and reaches over to turn it off, however it's actually a CB radio, which is incapable of picking up any frequencies that would be used by a police department.