At the end of the day, FEAR felt very much short of the expectations, just like the "smart gunships in Half Life that learned to shoot down incoming RPGs on their own" and the supposedly goal driven AI in STALKER which was never really implemented.
I didn't have any expectations, but FEAR AI was one of the best I've seen in games. I could replay the same battle over an over again, and the enemies did different, convincingly intelligent things, based on my own actions.
To be fair, the AI in STALKER (A-Life) was dialled down significantly prior to release as although it performed great, it made for a poor narrative experience as you could never really ensure it wouldn't break the game continuity in some way.
There are mods out there now that allow you to enable the full A-Life simulation and honestly it is very impressive even to this day.
I suspect that the gunship was simply programmed to shoot the closest hostile entity, which happened to be the player's rockets. This kind of emergent behavior is actually quite common in gameplay programming. In any case, machine learning was not involved in the development of Half-Life.
I remember playing FEAR for the first time a few years ago and being totaly disapointed so much that I asked Steam a refund. I think it's mostly because I've been playing CoD in the years before and it was too different and I couldn't make the switch to a different FPS style.
