Delta Parents

Yesterday morning I arrived at the airport, checked in and headed to the gate. The airport does not have screens to check the standby list so I pulled it up on my phone. On the non-rev standby list I was #2 out of two active employees with four retirees/other and one buddy. When i clicked on the airport standby list there were two S2 ahead of me, listed as S3. I looked at the names and clicked back and saw that they were retiree/other. I was a little concerned because there were only two seats available. A short time later they were called up and given the last two seats. I was 99% sure retirees do not get vacation passes so I decided to ask them about it. I introduced myself and asked the question and the wife responded "I don't know how we are listed, my daughter is an employee and she did it for us".
I did end up getting on the flight due to missing revenue passengers, but I still want to know how an employee's parents traveled on vacation passes. If I had missed that flight I would have been there for several extra hours and would not have been a happy camper.
Any ideas on how they did this?

how can S2's be listed as S3?
Was the employee the retiree? some cross lines and the parent is retiree but using the active employee status
Any active PNR member has same priv as employee--the trump is DOH and what priority chosen--
they can choose to change within a certain time frame using the red phones or askign the GA to change it in a timely manner
Non revs can't be S2 and S3 at same time

The employee's parents were listed as S2's... I was listed as S3.