GO
They didn't make a big deal about it simply because things like this happen all the time (although granted not usually on the scale of this). The production company can play run-throughs to test the format all they like and make adjustments but ultimately every game is different and some very last minute changes to format will occur when the game is played with a properly cast group of contestants in a studio environment as opposed to company staff in an office run-through or a one off unbroadcast pilot.
I know of one very expensive pilot in which an eventuality occurred that the development team had simply never considered before and they had to quickly figure out what exactly the rules should have been in that situation in order to continue the game. It all fell to pot after that.
The difference there is that there was a very real chance that contestants had cheated in order to win money and if that had gotten out, even with newly filmed episodes, then needless to say the press would have had a field day. Also it would have been important for the BBC to point out that it was 12 Yard's mistake and not theirs.
I think what the BBC did wrong was to try to cover this up. Firstly, people are interested in the making of television programmes, so why try to hide how something like this is made? Secondly, when the story inevitably comes out it's going to be with extra spin from the Daily Mail which is never going to be a good thing. Thirdly, it just looks suspicious even if they didn't actually do anything wrong.
I know of one very expensive pilot in which an eventuality occurred that the development team had simply never considered before and they had to quickly figure out what exactly the rules should have been in that situation in order to continue the game. It all fell to pot after that.
Apparently, the gameshow Perfection, also hosted by one Nick Knowles, had a problem where due to the design of the set contestants could potentially see the answers to some questions. Those episodes were scrapped and the contestants were invited back to play again. I don't believe there was any attempt to keep this secret. I don't know why things were different this time
Source: http://ukgameshows.com/ukgs/Perfection
Source: http://ukgameshows.com/ukgs/Perfection