Do you have a cite for "they had no intention of entering the bedroom"? In any case, it doesn't matter because by entering the apartment they were able to SEE that something wasn't quite as they expected it to be, so they were able to cast aside their intentions and enter the bedroom, something nannies listening at the door would not have been able to do. You still haven't explained what "nearby" means - how near is nearby? How many apartments per nanny watch? How far would the furthest point be that a nanny's watch would extend? Do you have any idea?
Yes I do. In Kate's case she was all set to return the door to it's correct location and go. She only looked into the bedroom because, she said, the door slammed as she went to pull it to.
Whichever way you twist it, they weren't copying the MW listening service and they weren't providing an improvement either.
The roads were open to the public, which Mark Warner complexes weren't.
The gaps between checks were twice as long as the MW checks.
They were unavailable between checks while MW staff were still out and about in the vicinity.