AJT is a cargo airline, presumably with a limited schedule to St. Vincent. I wonder what the logistics are in MIA because I would presume that cargo procedures are likely more scrutinous in MIA, especially for items going to the Caribbean. Could be a case of CBP holding the HR which is outside of the control of AC and AJT.

It also sounds like the family compounded the problem by insisting that the HR be transported on AJT rather than taking a more expeditious charter option after the mis-connect.