“What he did was incredibly brave,” she said, noting that Scott surely will face consequences.

“FINA has currently done more to reprimand Mack Horton than they have to reprimand Sun Yang,” she said.

Whether that is true no longer seems to matter to many top swimmers, especially those from the United States, Australia and Britain. Sun was just a toddler in 1994 when 10 Chinese swimmers tested positive for performance-enhancing drugs. China was subsequently barred from the 1995 Pan Pacific Swimming Championships, and the incident created a lingering veil of suspicion in the West.

While Sun’s method of rendering the test null and void was extreme, it is not unheard-of for athletes to express discomfort with some aspect of the testing process.

Travis Tygart, chief executive of the United States Anti-Doping Agency, said athletes sometimes balked at providing a sample for various reasons, and when that happens they are encouraged to contact a doping official to talk through their concerns. In an email exchange, Tygart said: “I’ve probably talked to 12 to 24 over the past 10 years to explain the process and answer any questions. Never have we had a sample being given and then destroyed by the athlete.”

Athletes tend to approach drug tests with the same attention to detail as pilots carrying out their preflight plane inspections, and for good reason: A positive result can ground careers and ruin reputations.

Nathan Adrian, an eight-time Olympic medalist, said there have been times when he has reached out to USADA officials for clarification about some aspect of the testing procedure. And if he was still discomfited by the collection process?

“I would follow the doping control officer and not let that sample out of my sight until it was at the FedEx station and gone,” Adrian said. “And on the way I would call USADA and find out if the paperwork was legitimate.”