Student- Teaching??

So my cooperating teacher was sick, and called out today. I, however, was present and did the lessons for the day.
The interesting thing is this, my friends... I am not allowed to be in the classroom with students without supervision. I mean, there has to be someone with certification in the room at all times. So, my cooperating teacher called for a sub.
Now, I don't doubt the necessity for the sub, or the validity of that policy. I do feel bad, however, for the sub. He just has to be in the room. I'm teaching... I'm reviewing homework... I'm passing back quizzes... He's reading the paper.