So... Elementary wants to be American answer to UK's Sherlock.
Sherlock Holmes in the present, just out of drug rehab. Lucy Liu acts a female Watson, a companion hired by Sherlock's father to keem him away from drugs.
It can be questionable to make a male-female detective pair, and then wait for the sexual tension to explode after seasons, like by Bones or Castle. And with an interest / job like theirs, it would be hard for the partners to keep up. So if they want to make the caracters likeable, and not jump from one bed to another, sexual tension it stays. At last that's my guess.
The line with the mirror... that was a good shoot. After that, the forgiveness was a bit quick though.
By the way... did you know that there is an actual Sherlock manga, made after the UK version?