The American, victor of four Olympic and eight world titles before retiring from the sport in 2000, was also involved in a lengthy debate with fellow athlete Steve Cram, now the lead commentator on BBC Television.
With thousands of Jamaican fans in the London Stadium getting ready to celebrate on day two of the championships, the 30-year-old was outrun in the final 30 metres by former Olympic and world champion Gatlin, who grabbed his first world title since 2005 at the age of 35. Johnson wrote on Twitter today.
The IAAF President Coe also gave away the medals to Gatlin, Coleman and Bolt as it's customary for the global body cheif to do the honours of the blue-riband event of the championships.
Michele Verroken, the founding director of sport consultancy business Sporting Integrity, told Julia Hartley-Brewer that athletes are looking at this "saying 'well what's the point of me trying to stay drugs free if the outcome actually is that I could still end up in a World Championships?'"
He responded to Johnson by claiming he had referenced other drugs cheats such as American sprinter Marion Jones and Moroccan-born Bahraini middle distance runner Rashid Ramzi. I thought Usain was very generous with the observations he made.
The American sprinter has been caught doping twice in his career, serving a total ban of five years.
Stunned to see their favourite Bolt losing the race, the crowd booed Gatlin while chanting "Usain Bolt!"
"There have been two bans in the past", Coe said, as quoted by The Daily Telegraph.
He added: "We created a villain and hero story that created most of this".
And Gatlin knew what Bolt meant to the sport, bowing in admiration in front of him, even after beating him.