Speaking as a former Instructor at CFLRS (I've been gone from CFLRS for over a decade), I'd like to make a point; IF you're told "Don't worry it has been taken care of", or words to that effect, I suggest you do follow up. If there was no 'words' from the Platoon Staff, including the Platoon Officer, to the entire course if/when something like this has been reported, that is usually a decent indicator the staff do not know about it. If people are not being 'interviewed/questioned' by staff, that could also be an indicator that staff do not know. If an incident is alleged to have happened, usually actions will be taken (informally and/or formally) to determine what happened, who was involved, is administrative and/or disciplinary warranted, should a UDI be ordered/MPs contacted, etc. If you're not sure if it was reported and you feel it is something that should be, ask to talk to your staff, NCOs, Officer, someone.
We will continue to have this crap in the CAF as long as it exists in Canadian society, where we recruit from. Personally, I've not seen or heard of anything like this in many years.
It is unfortunate the Duty NCO didn't go thru your Sector while this was happening, BTN.
I wonder, back in my day, if a bunch of guys ganged up on a weaker kid, they'd usually be the ones that were told to back off or they'd suffer some actual consequences. I've seen more than one kid when I was back in Elementary or Junior High get a shitkicking for picking on someone weaker than them. Bullies, some of them at least, learned lessons the hard way back then. Nowadays, it's about 'using your words' and softer approaches.
I wonder if that bites us in the ass as a society now...