If several users add defects or chat messages to a specific part of a document (or in the "overall" section found in the document or main review page), someone responding has no way of picking the chat or finding that they are responding to. Similar to an "Instant Message" environment, it makes it difficult for someone coming in later to go through & figure out the individual threads of conversation.
It would be great if a user could click on a chat or finding, and click a 'reply' button which would allow the UI to show the reply directly below the chat / defect that was previously entered.