When I was a child I was taught in all seriousness that, if the Nazis were ever to come to your house and ask straight-up ‘are you hiding Jews in your attic?’ (and you would be, because that's, like, the holiest thing possible) the correct response was to say ‘yes, we are,’ then to hold your breath and clench while you waited for God to swoop in and Jedi-mind-wipe the Nazis into thinking you'd said ‘no’ (and of course because God put the words there the Nazis would believe it and just go away.) This, despite the biblical precedents of the Hebrew midwives lying through their teeth to Pharaoh and ‘do not put God to the test.’ It always seemed a monstrously bad idea. (I imagined God shaking his head and muttering "am I going senile? Because I don't remember sending a fucking PLAGUE OF STUPID." God has a way with words.)
Or take, for another example, Tibetan buddhists. It's against their moral absolutes to kill animals, but it appears to also be against their absolutes to starve to death. So they will frighten yaks into running off cliffs and dying prolonged, horrible deaths on the rocks below.
The end result (animals dying) is of course exactly the same, but because they have to sidestep past a moral absolute, they end up taking the path of greater suffering.
Or take the Hindu absolute of not interfering with the sacred cow. What starts out as respect for the divine is twisted into something quite different when that absolute (‘don't interfere’) is taken to the logical extreme – Indian cities are crowded with diseased and injured cows, because medicine and care require ‘interference’ in the technical sense.
Want another example? Look at the increasingly ridiculous interpretations of ‘honour the Sabbath and keep it holy’ during the time of Jesus' ministry – all of which Jesus himself hand-waved past when he was hungry, or people were sick, or there was work to be done…
Moral absolutes are unworkable.