I take stories from when a +30 year old adult was 6 years old with a good dose of salt. I'm not really saying his friend wasn't killed, but the circumstances seem a bit questionable. A 6 year old crossed over someone old enough to drive, so 16+, so hard that the 16 year old fell over? This pissed the 16+ year old off enough to kill a 6 year old? The entire scenario is outrageous. 16 year olds are approaching full height, so likely in the upper 5ft range, possibly over 6ft. That person is in a basketball game with a 6 year old? The average height of a 6 year old boy is 42-49 inches, so 3'6" to 4'1". Not to mention the strength and coordination differences.
Boozer might believe this is what happened, but it sounds unlikely to have happened the way he described it.