I'm trying to figure out what actual law was broken.
Was it simply the improper paperwork (and corresponding avoidance of taxes), or is actually illegal to bring these artifacts into this country?
Not that I'm defending improper paperwork and tax avoidance, but the article seems to suggest a huge terrible evil act on the part of the HL CEO.
Probably just as well that those artifacts were brought here, before ISIS destroyed them.
There are laws which restrict and govern the importation of antiquities from foreign lands into the United States. They were enacted to address the plunder and looting of antiquities from less developed cultures to the US. Presumably there is suspicion that he violated these laws.
Just in googling a bit:
http://scholarship.law.cornell.edu/cgi/viewcontent.cgi?article=1049&context=clsops_papers
http://ndlawreview.org/wp-content/uploads/2013/07/Vitale.pdf