He said my speech was eloquent but my mannerisms were odd.
What made him think your mannerisms were odd?
I don't know. I think he was too harsh.
He was only grading your performance, he praised what he needed to, same with criticism. You need to accept such things will happen in order to improve your speeches for the future or else you'll just be stuck doing the same wrong things.
But I don't think my mannerisms were odd at all.
It may be that you aren't able to see what makes your mannerisms odd, but I'm sure he was giving his honest opinion. It's a good idea to reflect on things that you may be weak in, so that in the future you can improve.