It seems to be that the issue was not high expectations, but the lack of transparency of the expectations at the outset, and some expectations that were not related to task complexity. To effectively differentiate, the teacher should have spoken individually with the student (e.g. "you heard me give directions to everyone to_______________. That will require a lot of effort from most of the class, but that is something you already know how to do. Rather than have you work on something you already know how to do, your task will be to _______________. What you will be learning to do when you do that is ___________").
IMO, asking a student to re-do an assignment that wasn't differentiated when presented is not a positive experience for the child. My DD would definitely interpret that in a negative light. On the other hand, when she knows the different expectations from the outset, she understands that her teacher is thoughtfully setting assignments for students based on appropriateness for *that* student.
I think that what really caught my attention was the neatness issue. Neatness and task complexity are not synonymous. Unless the assignment was sloppy compared to most other work done by that child (indicating rush/lack of effort), it isn't reasonable to expect that a GT child is going to be "neater" then the other children. Being a strong reader or mathematician doesn't have much bearing on how prettily a student can put letters on a piece of paper.
