Quote ="Kevs Head"There may be other notes and interpretations but the following is in the laws;
"Penalise intentional interference 10.(g) If the ball is played quickly, all players will not necessarily have time to retire the prescribed distance.
They should be penalised only if they intentionally interfere with play – either actively or passively.
Accidental interference: If the interference with play is accidental, a scrum should be formed. Interference should not be considered accidental when the player concerned has had opportunity to remove himself from the area in which play is taking place."
This seems fairly clear to me - all the ref has to do is decide if the interference was accidental or not. So, in the case of the ahb throwing the ball directly at a prone player, clearly accidental so scrum (presumably head and feed to the prone player's team).'"
The scrum would be head and feed to the attacking team, they get a fresh set of 6 but don't gain any distance or the opportunity to take a penalty kick