I think Maisie was a bit unlucky in that she had a dance with a weird, but not particularly memorable concept, in a week where some of the less good from the beginning dancers did well — Jamie for example shot up the leaderboard, and Clara finished the show brilliantly.
I can't see Maisie's routine would have picked up many votes from people who weren't already planning to vote for her and because she's good, people probably thought she'd be safe.
So then in the dance off you have Maisie (very good dancer, difficult routine, some issues with technique) against Max (not as good a dancer but improving, easier routine, danced pretty nicely). And it's which of those elements do you give more weight to.
As an aside, I think it's why the scoring has got so high so quickly — they're trying to keep people's scores going up, but some of them started so high that there isn't much room for that! And if you give one person an 8 and then think somebody else is better then they get a 9 and if somebody is better again... well only 10 is left (although I wouldn't give a 10 if there were any obvious mistakes). Jamie and Clara both benefitted from that this week.
And finally, Dianne. I'm going to make a personal comment — I think she looks to have gone a bit too thin.