Then someone with a personal vendetta against him got his business records because of bad OPSEC. I'm sure a lot of other people involved (clients, business associates) also knew it was a questionable operation, but they were probably pretty happy to have health insurance actually pay for things that improved their health for once. I don't feel like this type of fraud would increase healthcare costs in the way many other actors in the system (who are not about to go to prison) increase them.
If this guy had been ordained as a doctor and was just a little more careful with the billing, he'd be hailed for getting insurance companies to pay for exercise treatment. "You say you have pain? I prescribe 'physical therapy' where you work out with one of my assistants for an hour and I talk to you at the end." Easy as that.