CBP: “When an individual is found with drug-related charges and tries to reenter the country, officers will take proper action.”
Assuming they're both referring to the same incident, the conclusion is that CBP is now turning back Green Card holders who have ever faced any drug-related charges. (It's not clear from the article, but the careful wording "has no active legal issues" suggests that he was convicted.)
The only question is whether they were looking before.
Most biographies have Jørn Utzon declining invitations to attend the opening and to later design the interiors in Australia (he did so remotely) after some major fallings out over cost with a new government after those that intially commissioned the work left.
eg: https://en.wikipedia.org/wiki/J%C3%B8rn_Utzon
https://www.abcalumni.au/utzon_finding_the_master_architect
It's difficult to imagine him turned away at the border if the record is accurate that he never attempted to return after leaving.
Seems hardly surprising, although "
following a tip-off by informants in London; his bags were searched by Customs officials, who found a large amount of what was then considered pornographic material, which included photographs, prints, books, a spool of film, some rubber masks, and sticks of incense.
I must admit I did think you may have confused a musician with the designer, .. although I'd pegged someone more in the vein of Percy Grainger (who's a bit too early in history and an Australian citizen so .. not) than Eugene.
Who hasn't been tripped up by an ex partner with an interest in the occult?
The architect and designer Jørn Utzon apparently never attempted to return after a falling out over funding and refused two invitations (to the opening and to return and design interiors ).
Perhaps the tour guide and yourself are thinking about the conducter who lobbied for the Opera House and got the project started as a concept.
If one were honestly pessimistic they might say that this is always done, but only due to politics is it being reported.