WASHINGTON — President Donald Trump’s doctor leaned on a federal health privacy law Monday to duck certain questions about the president’s treatment for COVID-19, while readily sharing other details of his patient’s condition. But a leading expert on the Health Insurance Portability and Accountability Act said a more likely reason for Dr. Sean Conley’s selective disclosures appears to be Trump’s comfort level in fully revealing his medical information.“That’s a little head-scratcher,” said Deven McGraw, a former career …