Unfortunately we have already lost track of the details of why this part of the algorithm workflow is written the way it is. Part of the difficulty is due to the "misuse" of the transaction system for two different purposes - i) the overall user transaction, ii) the workflow points where a complete transforming relay has been committed. It's clear that this implementation needs to be rewritten but we will have to do this after the release. The comment is a signpost to one of the most crucial areas where the algorithm needs to be understood better.