"Seriously, DS? You can't write this by yourself?"... Granted DS said, it wasn't a long response. He wasn't sure how long his answer would be when he requested the accommodation and started thinking of how to answer.
I share your disappointment, and your son's discomfort when I read this.
Because we did not see the paraprofessional's face, or her body language, or hear the tone of her voice in speaking to your son, some may believe it fair and just to consider whether it is possible that the paraprofessional anticipated a task of two lines or less, and believed she was following the IEP to encourage, but not require, DS to write independently?
Parents want to be factual, accurate, and unemotional in documenting.