That totally stinks! I hate it when they're mean like that.
I know the feeling. :-( I had a mean teacher, too, an art teacher. Actually, none of my art teachers really liked me, now that I think about it. LOL. I guess they didn't see me as artistic, so they thought since I wasn't interested in art, I didn't care for it, but I do appreciate good art when I see it, even though I don't think I make good art. I was never "creative" enough for them, either, whatever that means.
Although "good" art is still a subjective opinion, in a way. Oops, went off on a tangent.
Once, I was doing this drawing that was better than my others and then this guy jostled my elbow when he walked by me, the clutz and my pencil marked up half of it. He said, "Oh, sorry," smiling and I just looked at him and back at my drawing in horror, because there was no way to salvage it. And my heart was swelling with happiness because it was that much better than my usual drawings.
I was so ticked off, that I never drew during a class/lesson ever again seriously. Even today, it makes my head throb with anger to remember.
There was really no need to rip your drawing. Geez. Like you wrote, he could have kept it and given it back at the end of class. He was probably having a hard day and angry for some other reason, but took it out on you. I would report the bastard.