So the ability of this method to identify you based
    on your typing style would require a certain amount
    of consistency in the way you type.

Well done, you found the answer. A lot of people can't be positively identified, and the whole thing is error prone.

The meme should specify the headline is a statement with a question mark, rather than a proper question.

I.e. THIS POST TO BE DOWNVOTED?

Vs SHOULD THIS POST BE DOWNVOTED?