The review tool allows the reviewer to compare two revisions of the document, but it would be good if we could select one of the panes to view the revision of a file that the pin was originally added...
Status changed:
New Idea
to Implemented
Starting from Collaborator version 13.4 (which was released in Dec 2020) there is a version info for each comment/defect, created for specific version of the document under review. This version info implemented as a link, and if user clicks it then Collaborator opens corresponding version of the document in ‘Before’ panel.