It looks like the explosive force of the Poké balls is actually spreading embers from the fire. And as they fly through the air the dusty / gaseous suppressant

It looks like the explosive force of the Poké balls is actually spreading embers from the fire. And as they fly through the air the dusty / gaseous suppressant will be blown off, and the hard core of the solid glowing ember will continue flying to a new landing spot where it can spread the fire anew. Oops.