But that's the whole point - i.e. A legal system where the fact that a technicality (ID's forgetfulness) can actually prevent an important witness from taking the stand is wrong IMO and has lost sight of the reasons why they are all there in the first place.
Whilst I can see your point, I think you need to consider things in a wider context. Courts in all developed countries have strict rules under which they operate. Sometimes their refusal to hear witnesses or allow evidence may seem petty or counterintuitive.
However, if they allow any deviation from the rules then where does it stop? Allowing one person to give evidence because of a 'simple mistake' would open the floodgates in all future trials with lawyers claiming that they had made the same 'simple mistake'.
I think someone mentioned it could be the court just proving that they were in charge of proceedings - and this is exactly what it is. Think of it like a sport - the rules are freely available and apply to everyone.
N