Nah. They are detecting the collision in order to push the player, so the engine is doing the work already. They could easily add an on_collision_player event in the NPC controller that fires at that point to handle NPC reaction.
The age of the engine impacts things like loading screens, poor use of modern hardware, etc. The 2004-era NPC handling is simply a reluctance to do any more than the bare minimum.
This is the British meaning of surgeon, so just general doctor vs. doctor who cuts people up.
A police surgeon is a doctor trained in forensics. They assess injuries after an assault, whether a prisoner needs medical attention, etc. They are often a normal operating doctor who does police work when needed.