I certainly don't have the knowledge that you do on this topic, but could perhaps other jobs could count towards the 5 years, but they only need to be in Congress for a day? In my state, as an example, there are reports of state gov't workers who had a substitute teaching job for ONE DAY, and ended up getting hundreds of thousands more in pension money over their expected lifetime than they would have gotten otherwise (no, I'm not joking). They qualified on the "time" because of their other gov't job, but needed the single day of teaching in order to qualify for those benefits. (This loophole has now been closed supposedly.)