Teamwork and more

I just fail to understand why some people have no teamwork ethics. When you're working in a team its imperative to recognize other people's work and give them due credit for it. Maybe its because we are a part of a class and in school some students don't bother too much. But that's no reason to behave this way. I know I'm ranting but its for a very valid reason! I haven't had a very good experience this semester with some people acting the way they do. Last month, a team member changed the layout of the presentation just 30 minutes before submission time. A very upset colleague confronted her since she spent a lot of time the previous night working on it. And she was given the reply "Oh yeah, I changed it because I dint like the template". Now, this person was angry and without losing her cool explained that this is not correct work ethics and if she had a problem with anything should have brought it to her notice. A lot of explanation later, the incident was put to rest. One would have thought that the person wouldn't do the same thing again. But she did exactly the same thing the second time around.

What do you do with such a person? Do you shout and scream which is obviously not the solution. Do you explain calmly and voice your concerns that this behavior is not right and one will not get away with it in an organization? I just don't understand why some people behave this way? Is it because they don't think? Or is it that they haven't been taught such basic etiquette and manners?

Anyway, this semester is almost over and I'm done with group work for this class. The idea of having such groups and presentations in a business setting was implemented by our professor for a reason and clearly has been lost on some people.