TALLAHASSEE — The first thing Kate Pierson did after unlocking the yoga studio that November afternoon was set the mood, plugging in the soothing waterfall, selecting a cheery lemongrass oil for the scent diffuser. The thermostat was turned up to 98 for the 5:30 class. Hot Yoga Tallahassee was styled as a calming haven for a mostly female clientele. The men who practiced there, Pierson said, were men at ease with the “light and love” mission of the place. But the man who walked in about 5:15 that Friday was different. Pierson was still alone in the lobby when he...