I have not roasted this bean but have roasted several other varieties and have found that you get a few variations in each batch. I have removed beans that I thought were burnt or under done. I have also found what appeared to be empty husks in the batch. I think that this is normal as I have found these in every bean I have roasted.
I did a blend the other day that had a variety of beans from CS 7 through to CS 10 but it turned out very nice in the cup. I would sample some before I started removing any beans from the mix.
Best of luck :)