[Much like Remy, Angel is attempting to avoid people. However his reason has nothing to do with electric shocks. Instead, Angel is skulking in the shadows because he looks a bit like a monster and a lot less like a man. He has the ridged forehead, yellow eyes and fangs of his vampire face but his body is bulked up, run through with visible veins and heavily scarred. In short he looks like the monster he believes himself to be.
In his skulking and avoiding--particularly Buffy--he literally runs into Remy resulting in a strong shock that makes him growl and curse.]