The exact wording was a reference to what a police chief in Miami said in 1967. It was meant to evoke that event, which could easily be called “fanning the flames.”
Trump peddled a racist lie and conspiracy theory for five years, before he was even in politics. Birtherism. And before that, the Central Park Five. And before that the federal lawsuit against him and his dad for discrimination in housing. It's not plausibly deniable. And this is the same thing.
If it's genuinely not obvious, I'm surprised you believe a conspiracy that Trump was secretly refering to an event most people have never heard of, rather than rhyming.