Contradictions

so what am i going to talk about? Contradictions. As i'm talking about this, my dear lecturer is talking about statistics in the front, contradicting himself. hee. Not to worry, he is good at statistics. However, he keeps going back on his word of letting us off and keeping us back. x_X. Let's see.
1. On the first day of the lecture, after 1hr of the lecture, he said the rest of the lecture is not impt and we could go off. After 1 second, he immediately said that his supervisor might scold and kept us back till 2 hours is done.
2. On the second lecture, he said he has to go at 5pm as he has to be at Science centre by 6pm. In the end, we left the lecture theatre at about 5.40?
3. And in today's lecture, he wanted to give us a break. Just 1 sec after he said that, he continued with the sentence "Then when are you guys going to come back?" and continued with his lecture. x_X
What a guy. I seriously don't know what is up his mind. so strangeeeee....