I don't think with editing any conclusions can be reached.
You could have edited out: Diane apologising, Iain being asked not to put it in that freezer, and shown where his freezer was and ignoring that, someone completely different taking it out, Paul and Mary being told what happened, Iain removing his pants and sitting on Diane's ice cream... 
They could have put in a smirk from one of them when a joke was told them earlier, and edited it in to look like they were pleased about it all. Diane's comment about Iain had his freezer could have continued to say something like: "and we were all shown which was our freezer and told to make sure we only used our own" or "and I asked Paul what I should do, and I was told to take it out and put it on the side". Or they might have asked a leading question to get that statement out of her: "Iain doesn't have his own freezer does he?" reply: "oh yes, Iain has his own freezer, as we all do."
The thing is we can't tell. Just as we can't tell if the whole thing is a fix, and Paul and Mary decide beforehand who they are going to tell that their bake is bland/nasty/delicious.
Unless someone from the programme who you trust tells you what happened, then you can't know. And I suspect that anyone connected with the show won't be allowed to say anything other than the official stance, will they?