Just a couple of points about ????? ???? that seem to have been overlooked in this thread.
1. According to ????? ?? ??? ????????? ??”?, the ???? of ??? ???? does not require that the door be physically open, just that there is an expectation that it will be opened when the bell is rang.
2. If I recall correctly, in a situation of ??? ?? ??, the ???? of ??? ???? is not operative. I don’t think there is any doubt that an employer is ??? ?? ??.