Re: Fat luck on the recording
A friend who ran a small shop told me she had been conned into a very expensive utility switch. A famous energy company insisted she had agreed to a deal that she would (being canny almost to the point of being a Yorkshire lass) never have agreed, but were absolutely insistent she had assented on the phone.
We asked for a recording and actually got one. Listening to it I had the almost incredulous realisation that it was fake. I was able to analyse it with Audacity and prove beyond any reasonable doubt (in no small part due to a very fortunately timed quiet but distinctive background noise - the shop door bell) that the 'yes, that's right' which was supposed to imply consent to the deal was in fact a copy/paste of the response she had given when asked to confirm her address. The forgery was, despite a few blunders apparent only under a reasonably technical analysis, pretty good. When the police listened to the call, they assured me they didn't think it sounded fake - until I showed them the waveforms; then they were stunned.
Famous energy company, of course, blamed a rogue agent, and settled out of court, so unfortunately I was not a party to, as I had hoped, an actual fraud trial against them. Still my fee & reward bought me a new bathroom, so it wasn't too disappointing. But the moral is that call recordings, even when they are produced, may not be all they appear: record your own side (preferably on old fashioned cassettes with a nice bit of mains hum, and the radio on in the background) if you want to be sure.