I think perhaps you are right about her not phoning in, possum. I've been trying to find a link but I can't, but I do remember discussing it with my husband while watching the news (channel 9) so perhaps it was journalistic licence, perhaps gleaned (incorrectly) from the following:
'She had received a call asking her to come in early but told them she couldn’t. When she didn’t show up, they assumed that she had meant she couldn’t come in at all.'
~
http://www.couriermail.com.au/news/.../story-fnihsrk2-1227493800155?from=public_rss
Or perhaps this is where I've become confused too. if I find anything further, I'll post.
In the meantime, we will just assume that she DIDN"T phone in and did fully expect to be there at the time.