How is rude, unprofessional behavior by one student toward another student handled in graduate school? I just received a confirmation from my graduate program adviser that I successfully completed my two-year-long master's program. I had a negative experience in my second year because of a mandatory group project that I had to do in order to graduate.This group project was done under a certain level of guidance by a professor. The first semester of this group project was only one credit, while the second semester of this course was three credits. Much of the drama occurred in the last two days before the due date of the group's final paper, which was via email. I did not get along with two out of four former group members because those two bullied me and badmouthed me behind my back. It was evident to me that their actions were coordinated. Out of these two perpetrators, one was a female who was around my age (mid-20s), while the other one, the male, was 33 years old. I will only talk about the male here. 

There were three different paper drafts that we had to submit in the second semester of this group project class. Both of these individuals referred to were procrastinators and felt like the rules of the group did not apply to them. However, they were the most domineering ones in the group and consistently used foul language in group settings. The 33-year-old male was the group editor, but he was an extreme procrastinator who would literally wait until the last moment to do things. He did not do much editing in the first two drafts, and right on the day before the due date of the third and final paper, he suggested to the group to make huge changes. He hardly communicated with me, so I wasn't even expecting any form of communication from him. Besides, I had another paper that was due at exactly the same day and time as this group project paper. By the time that he started communicating via email to the entire group to make significant changes, I was already much more focused on my other paper and I looked at his email much later. He had sent me an angry message asking if I "still wanted to be a part" of the project. Excuse me, I was involved in this project, but he chose to be actively involved at the very end. I replied to his email, politely asking why he could not make his suggestions much sooner, despite his angry tone in the email that he personally sent to me. What he did in his response was that he broke down every single sentence that I wrote, and commented on how I was 'wrong' or did "not know what I was talking about." In the process, he even dropped the F-bomb twice at me and called me "passive-aggressive" for "challenging him." He was clearly the aggressive one. 
 He attacked me, saying that he was "not expecting me to make an effort." Despite his abusive words, I still made the changes that he demanded. 

Just one day after the due date of this paper, I scheduled an appointment with the professor and the associate dean at my school. I explained the behavior of this male. Their response was that his behavior was very unprofessional. I needed to have this meeting because no one, especially in a higher education setting deserves to be treated the way I was treated. This male referred to was interested in further pursuing a PhD. Besides, he was formerly in the US military, which is very surprising to me, considering his character issues and him physically being very out of shape. 

I was able to talk with the professor and the associate dean long before the conferral of degrees. However, I did not receive any updates after this meeting, which kind of made me angry. I don't know if the school took any measures or disciplinary action against this particular student. I don't know if the school actually took this issue seriously. Is it possible that no disciplinary action took place? Is it possible that students who exhibit such behavior get dismissed from the program for such unprofessional behavior?
For what it's worth working in higher education I can guarantee the professors have noted the unprofessional behavior from the student(s). In project settings it's fairly evident who is completing the work. Often universities or the specific schools within them do have conduct guidelines which if they were violated can result in removal from the program. Unfortunately, in the world you're likely to encounter these individuals as well and should learn how to address such issues as they may even be in a higher position in your organization.

It really depends on your institution on the specific outcome but be prepared as you will encounter this again and typically the actions they exhibit are systemic of lack of repercussion.