How would you figure out if someone is using an aimbot?

[lAimBotl]

Wondering how a average player could figure out if someone is botting vs skill, or walling of course. (I don't suspect anyone atm btw, just wondering )

 

[mills]

regular snapping and/or sideshooting

 

[Cassettes]

When you get instantly shot just for peeking, trust me you'll know, when they hit impossible quick shots.