Disclaimer: I own nothing but the original story line!
It wasn't a stand-off exactly; it was something a little more subtle than that. Sherlock had John's gun pointed at the discarded Semtex jacket, but then, Moriarty had snipers with laser sights, whose weapons were pointed at John.
Then he walked away – just like that. A phone call, a better offer, and he went.
More than a little relieved, the two men left the poolside and headed home, but during that taxi journey Sherlock couldn't shake the idea that something more was at work here.
He looked at John, who in turn was watching the passing scenery. John was lucky – more than lucky – it seemed that fate was often on his side. The evidence was clear; he had survived in Afghanistan – an injury that should have killed him; then later, back in London, the shot that killed Jeff Hope (well, he could have been a marksman), and the way he flung himself – despite being tied up – at Sarah, pushing her clear of that arrow, and now this. Each part of the game John had been involved in they'd won, including escaping Moriarty's trap
He frowned.
John turned and looked at him.
"What?"
"Who are you really, John Watson?"
"Just John Watson. Well, that's the name I prefer to use, instead of my real one"
"And what is your real one?"
"Beelzebub"