Well, it worked out and it was interesting to hear old Southwest cover themselves first.
I think I'd do the same thing these days, it would be good to know before calling the company.
And, if you said that the Delta Professionals had made a mistake, who would believe you without a corroborating witness?
Remember the not so distant 'good old days' when you might try a couple of takeoffs before taxiing back to the blocks with a configuration warning you were 'sure' was spurious? Now, you need to be redispatched if you've pushed the throttles up, released the brakes, started to roll and been told by the tower to stop and taxi clear of the active runway for flow control.
At least that is how I understand it, the goalposts keep moving on when you need an amended release, when you can enter an MEL item yourself, defer the deferral, and so on.
So yes, I spend a lot of time thinking about CYA stuff instead of flying the plane.
There is an audio link in this WSJ blog article where a Southwest pilot is similarly anxious to make sure the tower controller gets full credit for an earlier near miss on the ground at MDW:
Audio Recording of Midway Near-Miss Paints Picture of Southwest Pilot Concern - The Middle Seat Terminal - WSJ