I approached him and after he said to me "good evening" in a perfect english with no accents, he started to seem relieved. Then he told me that these days is really difficult to find an English person in London (obviously, he thought again that I couldn't be spanish, actually, judging by his reaction, I'm pretty sure he thought I was english).
He was looking for some help because, as he told me, ten days ago, a friend of him was robbed while...
he was sitting on the stairs of our bar tying his shoelazes.
As he was distracted, three eastern european men approached to him and started offering to clean his shoes but, although he rejected their offer, they insisted and started joking with him. When they had left he touched his left wrist and realized that he didn't have his watch.
The worst thing is that it seems that the watch was from his father, who in turn inherited it from his father and his grandfather, etc... So it had sentimental value for him and his friend was trying to help him looking for those people to offer them money for the watch (maybe 300 pounds as he told me).
I apologized because we didn't saw anything and we couldn't recognize this three men because many people goes there every day (the man was convinced that they operate every day in that zone). It was too much time ago and in London things happens fast, so I think that it's going to be impossible for them to recover the watch.