see, now that’s what I’m thinkin in my tinfoil hat. Somebody was supposed to get Marilou’s car of explosive delights over to the tanks. Boom. Then double boom. The shooter gets away, police are chasing shadows in 50 directions, Marilou’s name is written on everything, same as now, but she’s alibied - out of the country visiting her poor mom. And no, she’s not a victim. Ok, I’ll take the hat off.
The car exploding with all that ammunition inside, would be an incredible diversion. Or even driving the car into the tanks and exploding. Maybe his ISIS companion got cold feet or they hung him out to dry. Out of frustration, he fired a couple shots into tanks. The police would have thought the terrorist were attacking the airport if those tanks exploded or caught fire.