Probably time to Rule 10 this, so last post on it from me.
The referee has the discretion to stop the game if they believe foul play has occurred, or they can let it play (typically as a penalty advantage) and have it be reviewed concurrently. That is the protocol, and that is what happened here. As Wales was in possession, and it was potential foul play against Australia (and it looked like there may have been a small knock-on from Wales after the ball was cleared from the ruck), there was no point essentially playing advantage while the potential foul play was reviewed.
I would have posted a gif, but Stan's anti-screen capture tech makes it difficult. You said there was no head contact, so I chose that image as it clearly shows there was.
I would implore you to go back and watch both the real time and slow-mo of it (35:37 game clock). It's clear why Doleman may have thought there was foul play from the point of contact, movement of Kerevi's head, and the fact that Kerevi stays down. The AR in-shot is also on the mic telling Doleman as much. The slow-mo demonstrates there was indeed head contact, but it appeared exaggerated in real time due to the leading hand. Possible foul play occurred, it was reviewed, and a decision was made based on the evidence. The officials did their job.