Since you asked. Aikido.
I've taken some Hopkido which is where I was first introduced to the techniques he showed me. I'm head of security in a bar so he was showing me some control techniques. He wasn't hitting on a girl at the party either, his wife was there. I'm not slamming the BB, he's a great guy. Alcohol was involved and we were just screwing around in the yard a bit. Again, I find the art very effective but it's not always easy to get ahold of an attackers arm or wrist when he's 50, 100lbs bigger and swinging at you. The conversation began when I told him I'd thrown one punch in my bar in two years and his reply was he'd never throw a punch. Being someone with some experience in real world application I just feel that what works and looks inpressive in the dojo isn't always affective on the street.
I agree... it's always got to be adapted. But this is kind of what you might expect---if it's Aikido, where things like locks are the bread-and-butter of the combat application, then he might well have been expecting her to know, from the nature of the art, just what to do at that point. I'd have been surprised, though, if it had Gojo-ryu or TKD that were involved, because their locks are usually forcing moves to set up a strike to an exposed vital area (throat, solar plexis, base of skull, groin)---not always, but it's much more common. So in those cases, yes, a bit more explanation---kick the guy here, or elbow him there and keep the control going---would sort of be expected.
So maybe it's not so much a matter of him having been exclusive about his art as not wanting to have to state what he figured should be obvious to a student who'd been doing Aikido for a while (e.g., `Well, now you break his arm, duh'), along the lines Keikei suggested earlier. He might have just been leaving it to her to figure out, kind of a teaching technique---`I'm not going to tell you, you should be able to work this out on your own' sort of thing.