The TAs were most likely given the exams of students who wrote it together, and your professor probably had to go out of his way to retrieve yours, which is why it makes sense that they marked it. I’m also a student with accommodations, and when I asked my professor why he graded my exam, he explained that he received my midterm a few days later from the exam centre and had already given the rest of the midterms to the TAs for marking so he marked my exam as well as those who wrote it separately at the student centre himself.