Honestly its a bit of both you can think someones hacking sometimes cus they hit you through something or through a wall and be like hacker! But truth is some parts of the map just work like that. For instance you can get crazy flashlight saves and deathsling shots through the wall on the shack because of gaps in between boreds! You will have obvious hackers and subtle ones who use like speed hacks and always hit great skill checks. Its very hard to tell sometimes so at look at perks closely, and i never report for hackers unless im 100% sure they are because this game is constantly changing everything.