I hear a lot of holier-than-thou photographers blabber on self-righteously about the ethics of taking pictures in various contexts (and some of my favorite, highly-renowned photographers are guilty of this, too, though I still respect them otherwise). While it's true that one's dedication to art must be balanced with other concerns - as the unwaveringly honest photographer will undoubtedly end up either in stitches or in prison sooner or later - the photographer's code is incredibly simple:
Thou shalt never be ashamed to take a picture. The only shame a photographer should experience is when he sees a picture and fails to capture it, whether out of fear or laziness, or for any other reason.
Obviously, if you have to choose between taking a picture and preserving your life (if, for example, you were standing on the railroad tracks watching a train bearing down on you), you would probably want to save your life, as it's probably worth more to you than art. And I couldn't possibly criticize you for that.
However, criticizing a person for choosing art over other concerns (as opposed to merely disagreeing with their decision) betrays a fundamental lack of understanding and respect for art and the power it holds over our lives. You can call it antisocial if you like - I don't care - but I view social customs and legal restrictions as a frequent barrier to experiencing (and documenting) life in its truly natural, raw state.