Science fair partner not carrying his weight

I agree with letting it drop. You might let your son know that you don’t like what happened, that it really isn’t fair, but since he doesn’t want you to pursue it, you won’t. Another point you might make to him is that sometimes you really have to push to get what you need in life - other people won’t just hand it to you.

11’s not too young to start getting jaded and bitter, is it?

A lot of group projects that I did after 6th grade (didn’t do any at my private school before that) had us fill out a paper detailing what each person did on the project and rate each other (was the person willing to meet to work on it? did they do what they promised to?). No need to rat people out then.