The argument that this passenger had to suffer because in nearly every case where a passenger wants the staff to bend the rules their reason is manufactured doesn't wash.
When confronted by a situation where there is real doubt it is axiomatic that the passenger gets the benefit of the doubt, especially if the potential consequences of not doing so could be catastrophic, and the consequences of doing so are at worst inconvenience.
All she wanted to do was try and make a phone call. All the FA had to do was pass her request to the Captain, as per the Company requirement, apparently, and he ("the steward") refused to do that. (I do wonder if the personalities involved made calling the flight deck more difficult than it should be.)
All this stuff about people falsely pleading dying relatives at the check-in desk, as a justification for the FA's refusal to do even that, is irrelevant and, frankly, ridiculous.
It frequently saddens me when I see the industry in which I have worked for 40 years reducing its front-line staff to a bunch of jobsworth robots who are unable, perhaps not even allowed, to assess a situation properly and act accordingly in the service of the passengers who pay their wages. It hasn't always been like that.
This applies particularly to a minority of passenger handling staff on the ground, and a minority of cabin staff in the air.