Personally, I do not think it is correct for the judges to watch the rehearsals. They should see the routine the first time when it is on LIVE TV programme. Isn't it often said in the Skate Off that the judges have to judge the routine, not the previous performance? I do believe that everything the judges say to the constestants is scriped and approved by the producers of the programme. I think the "insulting" comments from Jason are used as a way of keeping the programme high profile as his comments are so often discussed in the media after the show. It is all showbiz people, nothing we see is real!! Same with X Factor, the producers have seen all the acts before the so-called judges watch the auditions and know beforehand who is coming on to perform. All the so-called amazement when a contestant can actually SING is acted!! Even the tears!!! I just hate it!!
Personally it doesn't bother me if the judges watch the rehearsals. In some ways it could help their judging as they can get an idea of the routine & what it should look like.
I also think it can help to avoid undermarking of contestants who perform early on. Gareth may have been marked slightly lower for example last night as the judges may have thought that we'll wait to see what Matt & Beth and leave ourselves somewhere to go. If Gareth had been 1 or 2 positions lower on the leaderboard that could have been the diference between him being in the skate off instead of Joe.
Of course the big caveat in all this is that the judges must judge/score on the performance in the main show & I feel that they do that. Jason may have cocked up his comments last night to Luke but I have no issues with how he scored him - & that's from someone who is not a Jason fan at all.