I think one more thing that might be added to that list (that would probably be the first to consider in this case) is the simple fact that pulling the stop may have "worked" quite often for him in the past. The occasions where he pulls the stop and thereby gives the trade enough room to work in his favor probably greatly outnumber the occasions where doing so lead to complete disaster. Which sums it up nicely. But I would say that our impulses are not as irrational as we would believe from the end results; pick up a searing hot pot filled with boiling water and we drop it instantly, even if it means scalding our feet and legs afterwards. It may just be that one's "subconscious" is actually doing what it feels is best, based on past history, in doing something that works more often than not -- the problem is simply that it's "miscalculating" or underweighting the potential damage when pulling a stop goes wrong.