I agree that would be ideal, but it's hard to expect someone who is so accustomed to not having to worry about such things to keep this in mind. This is especially true in situations where you are excited (eg: after giving a talk about something you are passionate about). Clearly he will not make this mistake again, it would have been the right thing to do for the organizers to take better care of him though and protect him from the risks of the country that they invited him to visit - at the very least within the walls of the conference venue.