OP here with another update.
DS was able to finish his experiment today. He did not finish it before school. He said he had to go in during study hall to finish it. I asked him what happened during the class period today. Videos. In fact, they didn't finish watching the videos, so they will be watching videos during class on Monday and Tuesday. The last day to work in class on the projects will be Wednesday. This means, of course, that any kids who want to work on projects Monday or Tuesday will have to come in early or use their study hall. As I understand it from DS, everything is due Wednesday.
I am so glad that I got DS there early this morning to do his experiment and that I stuck around to make sure the teacher let him do the work. He has that behind him, so he can concentrate on writing the research paper for the experiment between now and Wednesday. He will get it the A-layer work turned in, but I wonder about the other kids.
I asked DS if the teacher gave him a hard time about the fact that I was there this morning. He said she didn't say anything directly about me, but she did make a vague remark that he didn't understand and doesn't remember now. He said he told her that he didn't understand what she meant, and she said, "You know what I mean." He didn't.
I'm thinking that I may wait to approach the principal about all of this after Nov. 5 when the teacher says she will have the grades updated.