By rights the simple comeback is they can lie to you so F'em.
The real answer is you don't offer any explaination because it's not something you need to explain or get anyone's permission for.
Feel free to wonder. Give me a hard time and I'll just do my best to give you a hard time back. After you confiscate my stuff and detain me and I turn out not to have broken any laws, I'll do everything I can think of to extract an apology and compensation and penalty. Afro Man is my hero. You will become my new career.
That's my little fantasy anyway but I do see it as a duty to at least resist a little. In reality I'll fold pretty easy but I will be as much sand in the gears as I can.
When you object to being punched in the face, the problem is the punching in the face not the objection! If the bystanders don't like the fallout, "accept your punching more quietly and without spilling my drink" is not among the valid responses.