Myth #27 - The batter does not get first base if hit by a pitch after it bounces
A pitch is a ball delivered to the batter by the pitcher. It doesn't matter how it gets to the batter, if it is a legally pitched ball. If the batter is hit by a pitch (even if it bounces before it reaches him/her), while attempting to avoid it, he/she is awarded first base (of course, as long as they haven’t swung at it).
LL Playing Rules: 2.00 Definition of Terms: PITCH, 6.08(b)
The Right Call - Casebook of Little League Baseball (2004): Page 9 Comment on Definition of In Flight