I mean, I have a client sided aimbot that works currently and functions exactly as what it looks like in the video, so it might not be blhack. It just locks on to the nearest player relative to you. It's fairly useless, but fun to use on my server when I dwand idiots.
It might be possible that he could figure out where to acquire an old version of an aimbot and change like 5 or 10 lines to make it work again.