1. Sherlock Being Wrong
Because I made a blunder, my dear Watson - which is, I am afraid, a more common occurrence than anyone would think who only knew me through your memoirs. This is what Sherlock Holmes says in Silver Blaze. Arthur Conan Doyle was himself concerned that his creation would be perceived as too perfect, so he sometime had Holmes blunder. In The Yellow Face Holmes even remarks to Watson that if it should ever strike you that I am getting a little overconfident in my powers, or giving less pains to a case than it deserves, kindly whisper Norbury in my ear, and I shall be infinitely obliged to you. He wants Watson to remind him that he isnt always right. This kind of humility is really missing from the BBC Sherlock character and can have him coming across as too arrogant. In Series 2, to impress Irene Adler, Sherlock manages to make a break a code regarding airliners in eight seconds. Thats just too much. If theres no doubt as to whether or not Sherlock is right then theres no drama.