Presumably the DJs were given the number by someone? And the tape was checked before being aired. We can be angry with the DJs but they were just the weapon being held by others, higher up at the station.
Some have compared this to 'you've been framed'. No - with those kind of tv programmes, the victim has to consent to the footage being shown. Presumably not everyone does consent
This is more akin to viral youtube bullying but on an international scale, followed up by internet traffic calling for her to be sacked. I also note that all the UK media only played her voice, not the voice of the other nurse.
I am surprised people do not think it was a possible consequence. We do not have all that many examples to compare to. In most situations, it involves someone already in the public eye, say a politician or an actor, who is tricked on film or audio. They, I presume, do not have to give consent. It is a given that they have agreed to a level of media interest in their lives. We do have other examples, such as Dr Kelly, of 'normal' people thrust into the public eye who couldn't cope. On a normal scale, I am sure we can all think of articles we have read of people killing themselves after bullying by facebook, distribution of film of themselves to all in their school or workplace etc. It is certainly something I seem to read once a year or so, very sadly. So I would say it is a predictable but rare response to public humiliation.
Do I feel sorry for the DJs? Yes. I also feel sorry for people who kill others through careless driving. It doesn't mean it was not their fault, but there is no need to demonise them either. I feel incredibly sad for the family of this nurse and so sorry that this has happened and a life ended so unnecessarily.