There is always a chance that VAC Chaos can get you banned because it's public.
External ESPs are 99% undetected as Melodia says.
VAC of course knows about external ESPs but its very hard to ban hackers using them because they are external.
The Following User Says Thank You to TheUser For This Useful Post:
Usually the best way to avoid user error is to not be an idiot. In this particular case, that means make it look good. Don't get 100 kills and no deaths in one game or someone's gonna get pissed and pissed people are suspicious.