I think I heard a voice saying the son came up with the idea. He certainly didn't seem disturbed by the event, actually seemed to enjoy the excitement. The "rocket" is about as tame a toy, with obvious 'adult' supervision, as can be had. I think if the father had initiated this stunt, he would have had control of the firing mechanism. Half the time with these tooth-pulling events, the biggest obstacle is the fear of pain by the slow extraction. That's why the doorknob, string-on-an-arrow and the ever popular, string-across-a-street-waiting-on-a-car-to-drive-by methods are favored.
As for the mom not being around...Hey, it's a
man thing!
Frankly, I'm surprised that the string didn't cause the firing device to pop out of the boys hands. After all, the string was under his hands and the pulling force must have been all horizontal, if not downward!
And, the tooth may have been so lose that the boy feared speaking too actively for fear of it simply falling out! Strangely, this family doesn't appear to be from my area of the country; normally events like this are prefaced with, "Watch this!!"