Greg, I am very glad this was just a scare and everything turned out alright with Gordon.
It sounds like he didn't fall in face first, if he had the
mammalian diving reflex would have likely kicked in, he just would have went motionless face down in the water. That will give you a fright. We had this happen once when some friends of my folks were out with their little boy, he fell off the dock and his face hit the water, he instantly went motionless face down in the water and looked unconcious. I was there on the dock and pulled him out, it scared both of us pretty good. I am not sure where it's at but somehwere there is a crayon drawing of "Steve saving Joel".
Every pond owner should be aware of the mammalian dive reflex and young children, it can be a recipe for drowning if no one is near.
