Too late to the debate? This is the one episode that shows Sherlock to be significantly less aware of his own feelings than he may believe - decoding the MoD email in under a minute and finding within seconds the code to Irene's phone, which has eluded him for days. The power of desire and jealousy respectively? Combined with an incredibly competitive spirit - isn't that why Mycroft is his arch nemesis? I think Mycroft captures it when he says Sherlock used to want to be a pirate. Sherlock probably finds more excitement, competition and as a result attraction? in Irene than in most encounters in his life.
So in response to her move to belittle him, he hands over the code to her phone. Chess. Then adds 'Sorry about dinner'. Mate.
But eventually he cools down? Sees that her last words to him were the only sincere ones - and btw why did he need to take her pulse? Why did he care to know what she felt? And whatever he feels for her - fascination, competitive spirit, attraction, God forbid - love? - preserving her is important enough. For a little hop somewhere south of Karachi...