Oh what a load of toss.
Kristina looks more shocked than anyone each time Tess/Bruce call out their names in the results show. She
knows how rubbish John is, she even seems to get quite frustrated herself when trying to teach him to dance when he's blatantly not all that interested in (or capable of) improving.
If she was in James's boots last night I'm sure she'd be a little bit miffed as well. I think people seem to forget how much work the professional dancers actually put in. Yes, Kristina has to train the celebs and come up with routines like everyone else, but unlike everyone else she can't really up the ante week by week in the same way. She's pretty much stuck doing the same boring, basic routines week after week - only managing to make the dance interesting by putting in some positively fabulous dance moves for herself to try and mask John's crappiness.
I doubt a professional dancer would be have such a thin skin to be "offended" by the judges comments the way all of the OFCOM-friendly folks on here seem to be. It's a harsh, competitive world out there for a dancer. I'm sure if she ever did anything wrong when she was training she'd have got MUCH harsher criticism than anything the judges have said to John so far (which really aren't that harsh at all, tbh).
I also don't think she'll pass up the opportunity to return to the country's most-watched dance showcase, do you?
(P. S. Just in case my tone my suggest otherwise - Kristina is infinitely wonderful and by far my favourite dancer.

)