Well, in this case I'd probably say lore or academics would work as attack stats easily.
OK, a bit more realistic reason these rules might be used: Our theoretical players enter a warehouse where Bob the gun toting nut waits to shoot them. There's a standoff and the players realize very early that Bob is quite unhinged but in a straight out shootout there's no way that everyone leaves without some major damage. So they try something a little different...
Since Bob is obsessed with guns, and not particularly mentally stable, they try using their knowledge of weapons to see if they can't push him over the edge. They start up a conversation and try to convince him that his memory is wrong: he's got the safety on his gun on... did he use the right ammo? Did he assemble the gun right the last time he cleaned it? You know, maybe you should put that gun down, it'll explode and kill you if you screwed up.
Mechanically, I'd handle this as a series of social manoeuvres followed by one major mental attack. I'd probably let Bob defend with either academics or guns, and he'd probably start attacking on his turn anyways. In this case, the mental attack is delivered socially, but none the less it's an attempt to break him mentally, so I'd make the attack mental.
As a note: this is entirely situational. It's probably only worth it against someone who's mentally unstable (read: already has a few mental consequences in the first place, possibly from a different encounter?) Still, I'd love if my players came up with this kind of strategy in a campaign and figured out a way to exploit an enemies weakness rather than simply fighting him on his terms. As another note: I houserule that you have a different set of consequences for social, physical and mental tracks, so this might have to be handled slightly differently if you play by the normal rules (aspects instead of consequences on a person with this kind of weakness?)
