I was always unsure about Anton, even despite Katie's distancing away from the Widdy, Nancy and Judy dance ability comparisons.
It's Anton's fault for the lack of dance content, and I don't understand why he thought Katie didn't have the ability to do more dancing. I think she can be challenged more, so he didn't have to leave her doing naff all for those periods he did. I think part of it was him trying to get away with Latin dance property himself, let alone get Katie to do proper Latin.
Anton has danced in pro Latin routines so knows what is required to replicate Latin steps and moves, even if he doesn't look the most convincing himself. He knows Katie is worth more than the drivel of Latin dances he produced for lesser partners and needs to do her a service by at least getting basic content in routines for a start. As a pro he should be able to attempt that, and then work from there. Put aside his own inadeqacues of Latin dance ability and recognise that he should choreography more for someone that can do better (and will welcome the chance to do so).