[schoen]

I don't know that there is case law on this but I imagine that "prior to the admissibility inspection" is likely to be treated differently from "during the admissibility inspection" or "during administrative detention or secondary inspection" (or "in response to a request or question by a border agent"!).

Edit: a bigger picture question is the difference between things that may be legally punishable and things that may cause suspicion from CBP agents, which aren't the same thing at all.