Horton's arrows were aimed at three-time Olympic gold medallist swimmer Sun Yang. He labelled China's Sun a "drug cheat" before beating him to gold in the 400m Olympic freestyle final.
Sun served a three-month ban imposed by the Chinese Swimming Association in 2014 after testing positive for the stimulant trimetazidine. They accepted Sun's claim he had been prescribed the drug for a heart condition, unaware it had been added to the World Anti-Doping Agency's banned list less than five months earlier. But Chinada (the Chinese Anti-Doping Authority) did not report the failed test nor subsequent ban until after it had been served, effectively in secret.
There may be extenuating circumstances. Sun's heart condition is real and has caused him to pull out of events, but the secrecy looked suspicious. Meanwhile, French swimmer Camille Lacourt, who finished fifth in the 100m backstroke final just after Sun's 200m triumph, said swimming was becoming as tainted as athletics, "with two or three doped in each final. Sun Yang, he pisses purple," he told a French radio station.
Retiring Trinidad & Tobago bronze medallist George Bovell said this week swimmers are being let down by the people at the top, including Fina. "I see the cheating going on. I see the people with terrible technique swimming incredible times and people dropping lots of time late in their careers. The people at the bottom, like us, we just feel like... ancient Roman slave gladiators."
So the mute are finding their voice, goaded into action by the lack of it from the people running the Olympics and world sport. Don't give me that cobblers about everyone being innocent until proven guilty. Dopers and sports bodies have been hiding behind that for years.
This column has advocated many times a lifetime ban for dopers; institutionalised doping should be greeted with blanket ejection from world championships and Olympics. But the IOC and sports bodies know a protracted and expensive legal fight awaits anyone who tries to block a professional athlete from pursuing his or her trade; easier by far to do the Pontius Pilate thing. Efimova won a last-ditch legal appeal to swim at Rio in a court which ruled athletes cannot be punished twice for the same offence. So ban them once - for life.
You can also hear the caramel voice of the Establishment in the words of Vladimir Salnikov, head of the Russian Swimming Federation, in defending Efimova. "She has a long road to go in sport," Salnikov said of King. "I hope, and I think in the end, she will understand there are certain rules, there's a procedure that regulates the participation of athletes. She has the right to her opinion but you need to be objective and you need to be honourable."
'Honourable' is a strange word to use under the circumstances. The athletes clearly see honour in different terms. Maybe it's not quite the French Revolution but it is encouraging to see dopers feeling the sharp edge of the guillotine of public opinion.