The insider trades do not help at all.
As for the ADs, I can give a little info on this as I am currently a student studying to become a professional pilot and aviation management. From my understanding Southwest's whole fleet is 737s (as a business aspect this helps cut costs, labor, parts, training, ect). Now an AD is ofcourse manditory, I can see somehow it got pushed in the wrong box, or whatnot, but for it not to have been found for 3.5 years is no laughing matter. Somewhere along the line someone messed up BIG time.
My other thought is... it took the FAA 3.5 years to notice this... that's not good at all either.