That's not exactly true.
As someone who manages people, I've tons of experiences where no matter what kind of culture you try to build among your team (and believe me, I always put a big emphasis on team building), sometimes people just do stupid **** that you can't help.
I mean, yeah, you set an example, you try to consistently send the right message, but at the same time, they're grown adults, and they're responsible for their own conduct. And sometimes people just do dumb things. As a leader, you can't really change that.