I think the concern is that, if you tell an IAP "My child was tutored," they might possibly think to themselves "Despite all that tutoring, your child still didn't qualify?"
There certainly have been a couple of times that I've thought that in the past.
I doubt whether this question is in fact asked at the majority of appeals - because it's not a very good question. Assuming that the ideal answer is "No," how is a panel to know whether that is true? How can anyone prove a negative?
Some parents do not tell the truth. I know this from 'local knowledge' - where in an appeal the parent said their child had no tutoring. We allowed the appeal. In the playground I heard from a friend who said they'd heard that the appeal had been won (she was a friend of the parents - they were from another school), and she was rather surprised as the child had been very intensively tutored by a local woman known to push the children like crazy to get them through. I didn't comment on it but was privately annoyed that the parent had lied to us. They might have won the appeal anyway, but it's not nice.
We also hear from parents who say their children had no prep for the appeal, yet attend a private school who start doing practice in VR & NVR in year 3 and one year advertised that they had 100% success in grammar school entrance tests!
Hence it's not a very useful question for a panel to ask, as you'd have to more or less ignore the answer - it's not a quantifiable piece of evidence.