It's common knowledge if you've read any of her other threads.
There was one thread I can think back to that mentioned that.
I read the OP's thread as a general question. And no, for that answer, I don't think it's inappropriate to touch a child's knee while speaking to them. I think that the world has gotten way too sterile.
My 3rd grade teacher was the most sterile, hands off woman ever. She didn't even seem like she liked children. Generally, teachers/principals/counselors who are touchy feely actually LIKE kids at least.
Over the years, I've had teachers give me hugs, touch my arms, etc, etc. I've never thought anything of it. I also think that people automatically assume "man teacher/counselor touches child's knee = molestation."
Maybe the counselor knew that Hyia needed extra reassurance and put his hand on her knee for that reason?
If you feel uncomfortable (or Hyia does), by all means let the school know. Only you know what's best for your situation... but I personally don't find it to be a big deal, or even a little one.