I agree with Sidge - how can you sign a petition which provides such minimal information about what is probably a complex issue? Although there are a number of articles about the case there seem to be very few facts in the public domain. For example from the BBC notes about the documentary it would appear that she was recruited and paid by Panorama specifically for the purpose of getting into the ward to film, which would mean that she wasn't a whistleblower at all, but more of a mole.
Filming without consent (especially of vulnerable people) is wrong, but being a whistleblower is of course commendable. All trusts are required to have a policy in place, and those policies should mean that once you have raised concerns with your immediate manager (or their manager if the concern is about your manager) then there is a route to the Chief Nurse or often a member of the Board (often a non-exec for impartiality). Was this in place in her hospital (nothing to do with the Health Authority btw, although they would be a further place to raise issues, should the trust not have responded, and then she could have gone to CHI after that) and did she use it? I don't get the impression that that was Panorama's remit at all, and I can see why the hospital was very angry about the situation, as from the BBC story they had in fact acted on the complaints made, by investigating the issues (with their patient forum too) making changes and appointing a new ward manager. Perhaps too little too late, but these changes were not due to the actions of the documentary or this nurses actions. Of course the Trust should have been ensuring that such conditions didn't arise in the first place too, and poor care of the elderly is unfortunately still a real problem.
news.bbc.co.uk/2/hi/programmes/panorama/4655929.stm
On the other hand the NMC is fairly notorious for being harsh, so I wouldn't be surprised if this was an over reaction - being struck off for life is the most severe penalty available. That the RCN is supporting her means very little in my opinion - I have experienced them defending actions that really were fairly undefendable.