Why don't I get an error or notification if a job data row is not updated from a MSS/GSS transaction

I just had this situation come up today and not sure how to identify it happening in the future. A manager initiated a Reporting Relationship change through Manager Self Service. The effective date of this change was after the most recent position row, but prior to the most recent job data row. I would have expected to see some kind of notification when the position transaction automatically tried to add a job data row, and it could not because there was an existing row with a later date. Instead the transaction said