Cold sore after orthodontist?

I've had braces for a little over a year now. We go to a college and have students work on our teeth (my brother and I) because my parents didn't want to pay to send us to a real office. Yesterday, the girl working on my braces very haphazardly fixed my braces because I was the last of the day and she wanted to leave. I had four broken brackets and she was very irritated. Every time one of her peers walked by, she would make a rude comment about how many brackets I had broken. On the way out, my lower lip began to feel itchy, and the upper part of my chin began turning red. After about 6 hours, I got a sore, that looked kind of like a burn, on my chin. It was secreting a clear liquid, although today it is a scab. I have never gotten a cold sore before in my life. Is it possible that this is a cold sore, and that I received it from the unprofessional-ness of the ortho student not sanitizing all of the dental tools?