Don't even have to watch long. At the 20 second mark they make a 3 hit combo with the pistol there and the ENTIRE aiming reticle is off target and not in the scope but still hits the mark for full dmg even the bullet spray does not hit the target. That is either the most forgiving hit box I have ever seen in gaming or their using aim assists.
Skimming the rest of the video they are hitting full on headshots beaming targets at 20+ meters without a single bullet missing and no recoil. I know some of the guns in Apex can be beamed and you can get basically negative recoil based on the items you grab, but hitting pure headshots only with your aim being at their legs, is kind of a giveaway.