@Don & Steve: Yes, the correct word (‘whose’) should have been used. The “Dreaded Grammar NaziĀ®” once again turns out to be merely Human after all…
@Andrew: Perhaps using things like intentional typos and timed delays may be “dumbing down” the contest, but by the same token, it’s good not to “give yourself away” by answering too “perfectly”, or too quickly. That said, the axiom “All things in moderation” should apply, I think.
@Don: Good point about the bot “reading” the input as it’s typed (though I suspect that this is not the case with most chatbots), so a slight adjustment to the timings of the algorithm should be considered.