<p>@ OP: I don’t know this first hand, but several years ago I did hear a psychologist make reference to “calculator modification” on the GRE for a learning disabled student. He said it was exceptionally complicated, required a huge accommodation and committee meetings at the CollegeBoard, took a year and ton of documentation to achieve, and is rarely granted. From the way he told the story, I got the feeling he had once tried to fight for a student to get that accommodation and didn’t succeed. He called it a “big deal accommodation” unlike others that can be granted more readily based on a student’s history of prior test accommodations. </p>
<p>On the rare chance that was the situation here, it’s not impossible that the proctor knew about it for this student and was forewarned to permit the calculator. That could explain the proctor’s apparent indifference when you reported it. To protect that student’s privacy, proctor could be pretending to “not see it.” He can’t disclose the information about the other student to you, as it compromises that student’s right to privacy. </p>
<p>It’s a longshot, but not impossible, that’s what happened here.</p>