"Don't pour methanol directly on an open flame" is right up there with "don't drink bleach" for public safety announcements that make you lose faith in humanity.
There was a case in 2014 where an open container wasn't poured onto the fire. But during a repeat of the demonstration the residual heat reignited the fumes which went back into the container.
It's a common demonstration that maybe needs to be retired from K-12, since kids get ignited on occasion. I watched someone do it two years ago at an event, and if I had been in the front couple rows I would have moved back a bit.