“Just say no and give no details why one is saying that.”
Yeah, that is what I was thinking also.
Never give a commitment until you check things out, and then check your schedule, etc.
If you don’t want the job, you don’t have to do it. Just don’t tell them why. They don’t have any “right” to know why you refused.
Could be you wanted to catch a new movie at that time.
Forgot to add this: of course doing this necessarily lessens the honesty of the transaction, but I think that is fallout that cannot be avoided. Unfortunate, but a societal consequence of the feds regulating everything in sight...