Further to that Ghost - if I'm a parent, what assurances or guidelines are being given to me that my kid will be accurately assessed for a HIA?
The professional level of the game is much easier to police. They have the benefit of replays, multiple team medical staff and three fully trained referees who can spot this stuff.
A kid running around in the 15Ds is probably going to have a junior ref, some schoolmates as touchies and that's about it.
And I know the argument that these head injuries are likely more severe or more prevalent in the higher levels of the game. But I don't feel like that argument would pass the pub test for most parents.
		
		
	 
Just read this now.
I can answer this. If (and it's a big if) the potential concussion was seen by a coach/ref/manager sideline medico, then the player is removed from play and is issued a Concussion Referral and return form. It's a bit long winded, but the gist is that there are multiple checkpoints that the player has to achieve before they can return to play and the minimum amount of time for this is 21 days.
But here's the reassuring bit (although the amount of pushback I have received on this is truly gobsmacking). Having been hit, if a player exhibits any one of a number of different behaviours or symptoms, then that player will be categorised as having a concussion and will be treated accordingly whether they have actually received a concussion or not. Nobody can countermand this - including the doctor who must conduct further clinical assessment within 72 hours. 
So to answer your question, the Standard Care Pathway (the name given to the concussion protocol that junior and community players are bound by) covers off on the fact that there are no doctors with imaging equipment who observe the hit there on game day. It's a cautious approach and so it should be.