True enough - it does seem like an excess of caution (on the part of the man) that borders on the ridiculous. I have been in the position of walking behind another person, man or woman, in that sort of setting, and I do tend to slow myself down somewhat and stay back a ways, in order to make it clear that I'm not a threat. That seems to me like just a common courtesy...but, as you say, running across the street and apologizing for being there is too much.