Cluster disynchronization between nodes for programming rights

This is what happened on xwiki.org:

• I noticed that all pages on extensions.xwiki.org were displaying an error: "Failed to execute the [velocity] macro. Cause: [The execution of the [velocity] script macro is not allowed. Check the rights of its last author or the parameters if it's rendered from another script.]. Click on this message for details."
• I found out that it came from an edit of XWikiGuest on the http://extensions.xwiki.org/xwiki/bin/view/XWiki/Ratings page (which in itself is strange since this page is in the XWiki space which only allows Admins to edit pages but it must be coming from some script that we need to fix).
• Thus I rolledback the edit and it worked. Note that I did this change on a node (don't know which one but my guess is on node1, see below).
• This morning some user (Pascal Bastien) reported that e.x.o was still showing the problem but it was ok for me. I then forced checking on the other node (I was on node1 and I checked on node2) and indeed node2 still had the problem.
• Both histories looked fine http://extensions.xwikiorg-node2.xwikisas.com/xwiki/bin/view/XWiki/Ratings#History and http://extensions.xwikiorg-node1.xwikisas.com/xwiki/bin/view/XWiki/Ratings#History, which is normal since they share the same DB but apparently the PR was not given back to the page on node2.
• I then re-saved the page on node2 and it fixed the problem.

We need to understand why the first rollback didn't give back PR on the other node.