Actually the only thing Byrd's shot did (other than needlessly take the life of an unarmed woman) was delay the clearing of the last few people from the chamber. Who are you "protecting" when members would have all been gone by the time protesters even got to the doors of the chamber?People in the House chamber were in danger the moment Trump's thugs broke into the Capitol. That's why they were evacuated. And Byrd had to shoot to keep that violent mob out to protect those still inside the chamber.
Because unlike Ashes Targetpractice, they weren't breaching the police barricade. You think had someone climbed over it, which police guns drawn on them, the police wouldn't have taken that shot??
Protesters at the main door to the chamber had actually broken window panes of that door. Why didn't Capitol Police shoot any of them? Quite simply? There was no need!