I think it is completely weird that people think it is weird that they were worried and called. My employer would be calling me within 5 minutes of being late, and begin calling my emergency list within 15- 30 minutes if I had not called in, or they had not heard from me.
Any professional who sees clients, or is responsible for other people, cannot just not show up for work. I couldn't believe the ignorance of the 911 dispatcher on that call. Maybe service workers, a hairdresser, a waitress, cashier, janitor etc could get away with not showing up, but to think a small office of professionals, who know each other well, would NOT be alarmed is the stranger thing to me.