I wonder if Alfred could by taught to only fire off the script once a keypress timeout was met? So, instead of firing on immediate keypress, he waits for a very short time (30ms?) to see if another key has been pressed, only firing the script once no new keypress is registered. So, in the Avengers example, instead of firing on the press of 'a' it only fires once 'avengers' is fully typed, assuming you type 'avengers' quickly. Does that make sense?
I couldn't find conclusive data on how quickly users typically type but did come across Jakob Nielsen's findings that a 100ms response time is still perceived as instantaneous.
http://www.nngroup.com/articles/response-times-3-important-limits/