Myth #14 - A runner is out if he/she high-fives the coach while rounding third base (or first base), after a home run is hit over the fence
The rule states that if a coach physically assists a runner in returning to or advancing from first or third base by touching or holding him/her, it is interference.
Examples: If the runner falls over and the coach helps them up while the ball is in play, it is interference.
If the coach touches the runner at the point of a catch by an outfielder, to indicate when to tag up, it is interference.
If a coach physically grabs and stops a player from proceeding to the next base, it is interference.
The coach is not assisting a player if they exchange high fives on a home run.
LL Playing Rules: 7.09(i)
The Right Call - Casebook of Little League Baseball (2004): Page 31 Play 7-14