With Kid's the out of bounds is kind of subject to the ref's discretion, as the boundary usually is only a foot or so from the edge of the mat, where as in high school / college the line is the out of bounds but has extra mat beside it. I would venture to say the officials were erroring on the side of caution and preventing the kids from going out of bounds onto the floor.

Grasping of the headgear or singlet is a technical violation and shall be penalized accordingly. (I think it's a Technical, don't have my book to double check, but will get the rule as stated afterwhile.)