xkcd #3210: Eliminating the Impossible
Title text:
'If you've eliminated a few possibilities and you can't think of any others, your weird theory is proven right' isn't quite as rhetorically compelling.
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3210/
Very tiny grain - I feel like Doyle was a bit of a dreamer who was easily misled by confident adults and even children