SANTA ANA, Calif.—A 20-year-old Irvine man was arrested Nov. 1 on federal charges of attacking a flight attendant during a trip from New York bound for Santa Ana that had to be diverted to Denver. Brian Hsu was accused of assaulting the flight attendant Wednesday aboard an American Airlines flight, which took off from John F. Kennedy International Airport and was bound for John Wayne Airport in Santa Ana before it had to be diverted to Denver International Airport, according to federal prosecutors in Colorado. The alleged attack happened about halfway through the flight when the plane was over Ohio, one passenger said. Several witnesses initially told reporters that the attack erupted over a dispute about wearing a mask. But various media outlets in Denver reported that the flight attendant had accidentally bumped into Hsu—a first-class passenger—and apologized, but Hsu allegedly got out of his seat, walked to the airplane’s …