If a bird (that size) goes down the intake of a single engine jet (which judging by the photos was between 500-1000ft - I'd say nearer 500ft and in the circuit) and the engine winds down, you don't hang about to see what happens - you get out.
Oh my, yes...
As for the speculation about why the burner appears to be operating - the pilots first response would have probably been to firewall the throttles - either to avoid the bird(s) or as a reaction to a loss of power (seeing as closing the throttle at that height would be somewhat futile)...
Well, you can't see any flame in the first shot that shows the nozzle, but maybe that flash later was just from the engine coming apart with fuel flowing... it really is important to get away from a jet when the engine suffers critical damage- hot stuff, and high fuel flow rate... I'd take the ride in the seat over the ride down in that flying crematorium anyday!
But oddly enough, the plane wasn't too badly damaged when it arrived; wasn't trailing smoke on the way down, either.
Whatever- I can't blame them for punching out, and other than the plane, no harm done.