The Mercedes and Ferrari driver were in a fight for the Formula 1 drivers' world championship, and up to that point, relations were cordial between the two since both were enjoying battling each other on track.
The rivalry, however, came to a boil in Baku after Vettel accused Hamilton of brake-testing him under safety car conditions, which caused the Ferrari driver to collide into the back of the leading Mercedes. The reaction from the German was to drive up alongside the Briton and turn into him.
"He [Hamilton] brake-tested me," yelled Vettel over the team radio. "What the f**k is going on?" However, Hamilton gave his version by stating, "Vettel literally came alongside and hit me."
Vettel was given a 10-second penalty for his actions, while he escaped any retrospective action after issuing an apology. This seemed to sour relations between the two drivers going into the rest of the campaign.
What was a serious, yet fun, title battle between the two drivers turned into a more serious affair, with both hardly ever acknowledging each other for the rest of the campaign. Hamilton had the final laugh, however, when he overhauled Vettel after the summer break to seal his fourth world title at the Mexico Grand Prix on 29 October.
The 32-year-old has now revealed the conversation he had with the Ferrari driver following the race. Hamilton is confident that he would not have reacted like the German did, but understands different individuals react differently when put under pressure.
"When I spoke to him later, I was like 'that's a sign of disrespect, so don't ever disrespect me like that again, otherwise then we will have problems'," Hamilton said during an exclusive interview with Motorsport TV.
"I've never done that to someone. I don't even know what he was thinking to have done that... I've never been in a position like that.
"I guess people react differently under certain pressures," the four-time world champion added.