I have been lucky enough to interview a ton of people in my career. Before every interview, I try to create a checklist so it rolls smoothly. I'll study who I'm interviewing, I'll write down a core group of questions, I'll make sure my mic is on and/or the camera is rolling, ect. Now I have to add something to my checklist.
MAKE SURE THE PERSON I'M INTERVIEWING IS ALIVE.