You would also need to control for the degree to which people had a stake in the outcome (ie., virtue signalling).
Since executives have to make decisions where choosing the moral option may impose an economic (or operational) cost, this requires thinking through the actual choice.
Morality for the "rank and file" is just a signalling issue: there's nothing to think through, the answer they are "supposed to choose" is the one they do so, at no cost to them.
This study showed executives spent relatively more time on questions with moral/ethical concerns. Perhaps the control questions were more similar daily work and hence familiar, while there were fewer encounters with questions having moral/ethical concerns. Perhaps executives decided more care was required for these questions to ensure people were not hurt.
Getting back to the grandparent post, executives are certainly aware of situations with moral/ethical concerns and need not consult their barber to answer them.
"Rank and file" employees choosing to prioritize morality very, very frequently pay real costs for doing so - with a much larger personal impact than executives feel.
Only in very rare circumstances where the obvious answer and their procedural work dont align.
When making an operational decision that affects the direction of the business, morality is almost always a concern -- even at the level of "do our customers benefit from this vs., do we?" etc.
Where do you get the idea that those circumstances are "very rare"? Workers are being asked to break rules and do unethical things all the time, and you're pretty much guaranteed to pay a personal cost if you refuse.
Meanwhile morality is almost always one of least important factors when making operational decisions.
Since executives have to make decisions where choosing the moral option may impose an economic (or operational) cost, this requires thinking through the actual choice.
Morality for the "rank and file" is just a signalling issue: there's nothing to think through, the answer they are "supposed to choose" is the one they do so, at no cost to them.