Yep, I've seen her do it...because if they do it once, they will do it again and again. First, especially if the hrtm isn't there, people don't have time to be running around and looking up everyone's schedule, and second, since we don't know the new people as well, it would be harder to tell if it was really them on the phone or someone pretending to be them.
A couple of years ago, around this time of year, it was really bad, and we, as the operator, would do it to be nice, but we'd be getting several phone calls a shift from TMs who couldn't remember their schedule. I was able to put a stop to it when I just decided to start transferring them to the LOD who could use their discretion on how to handle it. Once they knew they'd have to talk to the LOD and plead their case with them, they suddenly got a lot better about keeping track of their hours.