The only down side, and I mean the ONLY down side is that he may presume that every trip will be like that....or he may become committed to improving on those catches (OK, that's not really that bad...)
All in all I'd say he earned a place at the rail for his next trip!
You've gotta love when a kid takes to fishing like that...it bodes well for the future of the industry as a whole!
It does make you crazy when you can get out-fished by a 10 year old...
