A flash bang triggers a concussion of sound and energy out a warehouse door and into the parking lot. A car alarm instantly cries out. Joshua Bobko is hanging back, carefully watching the West County SWAT team pour through the doorway of an empty Fountain Valley warehouse. The threat is a training simulation but Bobko’s concern is real. And the car alarm, of course, just keeps going. “That one second of unknown is crazy,” he says a few steps outside the door, dressed in tactical gear, including a weapon and protective vest. He’s the team’s medic and advisor, and he’s…