covert filming and public interest

Teacher-journalist Angela Mason, who was charged with unacceptable professional conduct for taking surreptitious footage in several schools for a Channel Five documentary, has now learned her fate: a one year suspension from teaching (1,2,3,4).
The core of the issue is whether the covert filming of students is in the public interest or not. Judgement on public interest is always a very tricky issue. It is so unambiguous and so controversial, that it has to be put in a specific context and anaylsed on a case-by-case basis.
I think we could borrow the way Lords judged the Reynolds case in which Lord Nicholas came up with the concept "responsible journalism". to be responsible journalism, the Lord remind that editors and reports should ask about ten questions to see if their reports really serve the public interest.
In this case of teacher-journalist, we could ask similar questions to test the ground for public interest:1. does the filming really serving the public interest by truthfully representing the reality?
2. is it really necessary to covertly film the students?
Regarding the first question, the supply teacher, according to the professional conduct hearing, the class chaos was resulting from her incompetency in managing the class although she didnot deliberatedly lead to that disorder. and many teachers did much better in managing students behavior. so in this sense, the class chaos filmed failed to do justice to the reality.
Regarding the second question, the students disorder has not been a secret, as many people have started to discuss the solution to the issue. of course, the filming could lead to more awareness of this issue, but it could not justify its necessity.
so in this case, the public interest test fails to be passed