My bad????

I sit back in my chair and type this from my lab classroom. I have just completed my TA and am sitting in an almost empty class now. Its not going to be long before the next lab students are going to storm into the lab. I just had a really rough day so far like one of my students did. It all went really well until she for some reason didn't save her lab exercise though she completed it. Students had to type in a Word document which said they would follow all the rules etc, sign it and turn it in before they left the lab. The student called me and asked me if it was ok for her to modify her friend's work and print it out and turn it in. The very first line of the assignment read "I shall not copy or share my assignments..." Apparently the student was mad at me for not letting her use somebody else's work. But I could understand her frustration as the document she had to type was pretty long. But was it my fault?? She didn't print it out or save it. Why was she mad at me and for what? For me being fair? Is this what I get for being so? Throughout the class I had to bear with her mean attitude,mumbling and bitching. Was this what I am supposed to get for trying to stick to the rules. This has clearly upset me but its time I get it out of my mind because life goes on this way and the students have started entering my lab classroom now. I have tried to be fair and just and here I blog..