Is there a way to kill an unresponsive applescript launched by an application without killing the application?

I've got an AppleScript that I usually launch out of Quicksilver, but occasionally, the script hangs, never exiting. (I think it's waiting on a non-existent window to appear).

This results in Quicksilver being monopolized, waiting for the script to die off.

If this were a Windows box, there would be a "scripting host" process I could end to fix this, but I'm not sure if OS X has a similar process. Nothing jumps out at me in the process list.

Of course, I could just kill and restart Quicksilver, but I'm wondering if there's an explicit way to just kill a runaway applescript that's running in the context of another application?