Under some conditions it may happen that a commit to the DocumentStore fails with a ConflictException even though there is no conflicting change. This includes regular commits as well as branch commits.
The actual problem is with NodeDocument.getNewestRevision(). This method is used in Commit.checkConflicts() to find out when the most recent change happened on a node and find conflicts. The returned value is incorrect and may e.g. return null even though the node exists. This will then trigger the ConflictException.