sometime i think the pace of DS9 is tooooo slow, but maybe its the valium
But you don’t know who’s the changling. He could be pretending to be a locked up Bashir to get them to shoot the real one. (Were they on stun settings? Would that work?)
At least aiming their phasers while they were unsure would have given them a chance to react once the changeling transformed.
I mean, rule #1 of firearm safety is not to point the loud end at something you don’t want to kill, certainly not a colleague… not sure what they teach on day one of Phaser School but I suspect it’s not too far off!