1. When Dumbledore placed an infant with a family who just had a baby and didn't offer any sort of stipend from the child's massive personal fortune.
2. Also when Dumbledore didn't send anyone to check in on Harry's well-being for eleven years, instead relying on a Squib down the road who was powerless to intercede regarding his welfare.
3. When McGonagall rewarded three tweens for taking down a class XXXX magical creature instead of sending a strong message to the student body that vigilante justice is not tolerated, for everyone's safety.
"Break the rules and profit," that's what I always say.