Not sure--I guess she thought that they were not obviously diverging and his reading was fluent. If it wasn't fluent then she probably would have investigated more. It was obvious though that there was a big difference between tracking "on command" and what happens naturally to follow print while reading. I have watched him read as well (by sitting across a table from him and watching his eyes) and they move very fast and seem to track well together. I would be interested in having the computer program watch his eye movements and see what it picks up.
