It's not always hacking, this is what I don't like about some admins decisions when it comes to hacking, they cannot Anti-Cheat for certain reasons, they give that power to head admins to see if someone is hacking or not. Unless it was something obvious like god mode or speed hacks then yes by all means stop them but if it's something like this situation just leave it until you fully on know he was hacking, There are scripts that can get past emps system like some esp scripts that TiGzTeR caught someone using but unless you have Anti-Cheat you shouldn't be assuming he is hacking by him 1 shoting you in the head, The M4A1 can do that with 2 shots, what if a guy shot you with a psg at the same time as him in the head and you didn't notice it was two shots and it seemed like one.
Here is a little tip I advise you admins who are banning people for hacking follow.
Warning: Spoiler! [ Click to expand ]