Kilburn pubs I remember from years back, and they didn't have a safe sort of feel... You were no doubt very wise not to take pictures, you might have found yourself up against (the wall and) some mean and possibly Special Branch coppers.
As I remember it, the cops were very psyched up - now one thinks of the case of the young Brazilian shot on suspicion in the tube in London. This was the time of the conflict in Northern Ireland - and with any sudden movement one of them might have shot first and asked what I had in my hands afterwards - especially as it was a SLR - not the friendly little Lumix :-) Maybe it's because I'm a Londoner - that I moved to Nice.