The premise of this scenario is the fact that it's a toy gun and you know it's a toy gun. The premise of the scenario leaves no wiggle room on that and is unequivocal.
i will unequivocally know it is a plastic gun when he drops it on the ground
either cause he sees me pointing a real one at him
and i told him to, or
he runs away or
cause he drops it when my real bullet misses him by a skinny--OMG, can you believe after all my years of practice that i missed my target??
in Connectidut there are a lot, a real lot of strange laws related to guns and use of force. but in a nutshell: if someone profess to have, even without showing it, a dangerous weapon (knife, gun) you may respond with deadly force if you feel your life is being threatened.
lots of 'kids' painted their bbl with the orange band years ago to fool people into thinking there gun was a toy. go figure.
after a few shootings by police of kids who really had toy guns, the laws got written so as to protect the police from civil suits ( i probably do not have this right as in legal speak, just right in a 'the way it is')
but as shooting some one is the last thing i ever want to do; given that i have not shot people who had real guns--it is very, very doubtful that i would shoot him either.