I remember the FE "dual citizen" situation. While it was red meat for the PID folks because of which airline's list(s) the pilots involved were on, it really wasn't anything uncommon, then or now.

Its always been airline managements' policy at every individual airline as to permitting a pilot on one list to have a seniority number on another list. It still is today. Some airlines don't care while others are adamantly opposed to it. Even the ones against it have little control over what another airline does with pilots on the first airline's list. For example plenty of pilots were required to write seniority resignation letters to work for certain airlines, like Delta and Comair.

Many other airlines never required anyone to write anything. Even the ones that did/still do require resignation can't really enforce it because some airlines, like United and American (among MANY others) tell (or at least told at the time in question) their furloughed pilots to write whatever letter they needed to in order to get a job and they were assured those letters would go straight to the trash. Delta, OTOH, strictly upholds seniority resignation letters, even if written in duress while on furlough. That is a Delta policy that most other major airline pilots do not have to deal with in their hour of need.

So for example a furloughed UAL or AA pilot (among MANY others) was free to write a meaningless resignation letter to appease Comair's policy (or any other airlines') but Delta pilots were told if they did any such thing (to get hired anywhere else, not just Comair) they would be off the list forever. ASA policy didn't require the resignation in the first place as a matter of ASA management policy, so furloughed Delta pilots were able to go there without writing the letter that only Delta among the "majors" would enforce.

As adamant as Delta management was about their "no dual seniority" stance, like you mentioned, they were willing to waive it for the PFE's to meet company mins, even though they controlled the mins and could change them at any time, to allow dual seniority for their specific case. Right or wrong, the PID/RJDC saw that revelation as the smoking candlestick that Col. Mustard used in the library and tried to elevate it to a much higher significance than it was. The Delta MEC was later able to hide behind the emotional smoke screen by capitalizing on the anti Comair demagoguery by blaming the Comair MEC for not changing a Comair management policy that required the writing of a resignation letter while at the same time completely ignoring the fact that the Delta MEC was unwilling or unable to get Delta management to change its identical policy that put the furloughed pilot in that situation in the first place.

The very same policy that furloughed pilots at other majors never had to abide by, not even by their otherwise hostile management teams. So why was Delta the only major airline that required furloughed pilots in need of a job to resign on their end when others didn't and in fact actively encouraged their pilots to find other work while assuring them that their jobs were safe upon return? Why was the Delta MEC the only MEC that was unable to change their own airline's policy for their own pilots?