Depends on if the torch is pressure regulated or not.
If it is not pressure regulated liquid propane works it way out when the torch is inverted. This is why unregulated torches blow out when you tip them upside down.
With a unregulated, there would be no ignition until the liquid propane dissipates enough to get the Air/fuel ratio down to ~ 15.67:1. By that time there will be a large volume of propane around the torch .... flash as it all ignitions at once.