I believe the rifle in question here is an SBR under US law. Keep in mind it was printed in Canadia (eh).
I wouldn't suggest downloading the STL for it if you have a 3D printer (coughconstructiveposessioncough).
Having STL's for other stuff is fine since you can build anything you want, but SBR's still have to be papered. STL of an SBR + 3D printer = damned easy win for a lazy F-trooper.
Good on them for shooting 14 rounds without failure. I bet putting some hose clamps around the chamber section of the barrel would result in significantly longer life of the firearm.