The guy appears to have successfully entered the US (his tweet was sent from Manhattan), so apparently he passed their test. He also explicitly stated that he

The guy appears to have successfully entered the US (his tweet was sent from Manhattan), so apparently he passed their test. He also explicitly stated that he refused to answer the BST question and they moved on to other questions. Meaning it's not even speculation to claim that they weren't requiring an accurate answer to the BST question for entry: it's demonstrably true fact.