FIFA has huge flaws every year too, let's not go crazy. I couldn't tell you what governs the goalie AI. I don't think that's the reason why such easy goals go in sometimes, as far as CPU scoring in player. I think it has more to do with the places (finesse shot) being overpowered. I think the CPU uses the finesse shot any time its inside the box, devs just need to nerf it.
As far as scoring in the CPU, I have noticed that if you go into the box head on and blast it directly at the keeper, it will more often than not go in. I think therecmight be certain blindspots to the goalies AI. I don't think it's scrpited, just something the devs either missed or messed with for final release, because playing the demo again the goalies seems to be a bit quicker to react.
Ultimately, I think (hope) Konami knows about all these flaws and are trying to figure them out. I'm guessing this is why the first datapack is taking so long.