So what's the point in providing Collaboration Certs then?
So that the prosecution can adduce evidence without having to produce a witness, thus saving time and expense. The absence of a certificate just means a witness would need to testify that the camera was working, and unless you could undermine the witness's evidence you'd be convicted, certificate or no certificate.
The fact that people would like certificates to be legally required is a bit like life after death: it's a nice idea, it would make many of us very happy if it were true, but the fact that we would like it to be true does not make it so.
If you want a defence, you'll have to find something else to argue.