Editing operations and spliting segment

Hi Fredrik, all,  I'm working on integrating the rules for editing a target segment in the draft.  For the part about editing when there is an existing target one of the PEs is:  MUST NOT Split the segment into two segments  And the text explains this as: "The reason to not allow splitting of segments with content in the target node is because there is no guarantee that the content in the two nodes are linguistically in the same order, allowing that operation would pose a risk to the integrity of the content."  I'm not sure what "there is no guarantee that the content in the two nodes are linguistically in the same order" means, and what nodes we are talking about.  Could you elaborate and/or give an example if you have time? (if not that's ok: we'll clarify this when we get to it during the F2F)  Thanks, -ys