Then they’re not doing it right.
Whenever I had a Paladin like this and gave him a holy avenger and made him choose between the holy avenger and an innocent child’s life. These guys always chose the holy avenger in some way that they reasoned wouldn’t make them lose their paladin hood.
So, did they all enjoy the sword +1 they got?
as a DM I would find a way to kill them off, as a player I would usually murder them outright. My most played toon was a dark elf magic user thief, intelligence was very high and he had long term goals…Chaotic evil goals but goal none the less. that type of game play was bad for the group and bad for the character so when they did something dumb with the “its what my character would have done” I would usually backstab them combined with a self made shocking grasp type spell of much higher level. then when they bitched I would just hit them back with the same line.
but if they wanted to try again without the dumbassery I was always willing to forgive.