> a notable example is the guards on the dam which can't see you until you approach their walkways and this is because the STANs at the top of the ladder can only see those at the bottom.

It's a credit to the game that I never noticed this and other AI shortfalls. Somehow the combination of fast paced action, tense stealth gameplay, level design, and good enough AI was enough to transcend any critical faculties I had. I guess the lesson there is whether it's CGI, VR, or game AI, when you understand your limitations and design to them, you can get the audience to do the rest of the work in their head completely unaware of the shortcomings that are not only hidden from them but that they may be compensating for.