[afavour]

> extremely unlikely

Very true. But the point the OP is making is that your entire fate is in the hands of a CBP officer and they are a very, very mixed bunch.

I repeat OP's advice to avoid a land crossing, I'm not sure exactly what it is but I suspect partly that land crossings have much less time pressure. I've had my car pulled over and partly taken apart looking for "anything suspicious". We were two men in our mid twenties and I think the agents were just bored, honestly.