The assignment requires that he pick six people he knows and writes about them, then pick one of which will be the topic of a fictional story. These sorts of assignments have been trouble in the past, as he is "embarrassed" about sharing his feelings regarding people, even if he can fictionalize the individuals. We tried a number of tactics, such as reassuring him that only his teacher would read the assignment, but no go.
Are you sure it's embarrassment about his feelings, or his inability to understand, interpret, and express his thoughts in this sort of assignment?
Did the assignment give explicit, concrete examples of what type of information he was to include about his six people?
My DS12 (ASD) has a lot of trouble with this sort of thing, also. He tends to shut down and refuse to do it, also, or gives very minimal, concrete answers that appear to be refusal.
With the last (similar) assignment--I helped him by working with him to deconstruct the directions, gave him feedback about what the teacher most likely expected to see, and typed it for him. A little overboard, probably, but it really helped me understand what was going on in his head. He really didn't get it--it wasn't refusal per se, but inability and frustration.
It might be more useful for your DS to have some help working through this sort of thing instead of allowing him to avoid it altogether. I'm not sure about that part--but I am sure that our program would not be on board with allowing DS to skip assignments where he struggles. It sounds like your DS might need extra instruction and help with this kind of thing, but there could be some useful learning and information to be gained by working through it.
