I believe they are paid a fee per assessment so it's in their interests to get through as many as possible in a day.
Yes, they're cutting and pasting all over the place - I've read posts by blind people who made good eye contact, double amputees who straightened both their knees fully and a lady who is an elective mute who communicated well with the assessor. One parent was asked how her son 'caught' Down's Syndrome and whether or not his condition was expected to last more than nine months.
Half of my own conditions were not listed, nor were they even mentioned during the assessment. Several of his observations did not match the points he had given me. I'm waiting for the DM decision then I suppose I'll get ready for the MR!