Just notice that the most easiest way to kill a bot is just to run on them and no brain shoot.
At some point, when shield is down, bots are just turning around and tries to run, which is impossible since you are already close…
I think that must be fixes. Instead bots should give you a head shoot, just like when you are camping with sniper rifle, while aiming. Bots should punish players for such “berserker” runs on them.