I've known other examiners to make similar comments for rapport/encouragement/motivational reasons. I try to avoid those, myself, because my experience is that kids don't always interpret them the way you expect. It's usually harmless, but my preference is not to. Those who give the WJ are particularly prone to doing so. Maybe because there's a handy chart right on the record form, next to each subtest, with approximate age equivalents on it.
Keep in mind, also, that while it is normatively unusual for a six yo to answer most questions administered to 14-16 yos, there is a big difference between answering the first question typically given to a 14-16 yo, and answering items that the 50th %ile of 16 yos normally get correct. And, I can't help mentioning yet again that age equivalents are the work of the devil.
