I am reading this paper of Rezk's http://arxiv.org/abs/0901.3602 , and as it is pointed out in the introduction, it contained a wrong statement (2.19 in the old version) and now there is a new proof for the main result, which is 6.6. Now, section 6.9 of the new proof refers to Prop. 6.4, which uses 2.19 towards the end.

Am I missing something? How is this apparent circularity resolved?

Thanks in advance!