Didn't know about this cave bug. But thats not what I mean.
There is some way to exploit "something" to get more AP. (don't know exactly what or how but I think it has something to do with Nuka Cola/Nuka Cola Addiction/Chem Resistant)
I heared that you can do it again and again, to receive more AP. Also I have a sreenshot from a guy who has 31AP.