Finger pointing

In the Agile dev world, there is a rule saying 'no finger pointing'. This means not rubbing people's nose in something when they made a mistake. This to assure people don't become afraid of touching some code or making mistakes. I think it's also a way of being professional. Now here's the thing. Most people want to know when they made a mistake. So you need to tell them. It's about how you tell them of course. Polite and calm is the manner it should be. This works for most people, but the rule has a couple of disadvantages: What do you do when someone really doesn't give a f*ck? You already told him 10 times to run the tests before check in and he still doesn't do it. What do you do then? I say finger point away! Finger point till he cries :)