The liquor analogy would be if you ordered a bottle of liquor to be shipped to the US and the liquor store would be expected to comply with US import rules.
> liquor to be shipped to the US and the liquor store would be expected to comply with US import rules
It may want to comply with the rules, because the parcel will bounce at customs, but if there are no export restrictions, it has no other reason not to send a bottle into the US.
Except to serve it's customer, because if it doesn't meet import requirements then the customer's package will never arrive. I understand it may not be legally obligated so there's no repercussion except the shipment being confiscated, but it's in business to serve customers.
Carrying stuff you bought on an overseas trip through customs is not "importation" for legal purposes.
Also, export restrictions are different from import laws. Export laws are applied by the seller's country. The buyer does not have to comply with export laws. Import laws are applied by the buyer's country. Both the buyer and seller must comply with import laws unless the buyer is an "importer of record" in which case only the buyer must comply with import laws.