The people who really confuse me are those who have a different response for a billion people vs five.
Seems like an easy enough explanation--they weight autonomy > 5 lives, but < 1,000,000,000 lives. What their exact weighting/break point is, I don't know, and neither do they, but I can see a rationale where their answer changes at a certain threshold. Mine doesn't, but I do understand it.
Of course, I generally think people who are inconsistent with it is because they're going on gut feeling at the second, and haven't really thought it out. That's the majority of inconsistencies, IMO. But I do think there could be someone with a thought out/developed opinion that is "inconsistent."
As for Bertram's comments, I don't think one can "answer" these in freshman philosophy and be done with the question for their entire lives. I think one should revisit it, because one's personal values change, amount of empathy changes, experiences change, etc. It's worth revisiting and thinking about these questions, IMO.