I think OP is referring to a job site where people coming and going have access to the panel. If you're home alone or only have a small handful of people to keep in contact with then it's far less of an issue.
In those cases you're 'probably fine' but if someone gets home while you're working, sees that the power is out, and goes to check the circuit breaker (as you've probably trained them to do) then you could still get zapped without warning.
