Stop in for a cup of coffee

Sure seems like bad luck, but try to do a careful postmortum. Gas spillage plus a spark or very high heat source was needed to ignite it.
At the fuel pump its an inverted flare fitting. I'd think its pretty hard to split the line at the fitting. But you'll find out when you take apart.
I’m actually a bit surprised it didn’t ignite the gas in the line and travel back to the tank where a fresh 15 gallons of 93 octane was