actually, in rereading your post, i have to concede that your friend didn't say that JKD was telegraphic and easily defeated. he made that observation about the guy he sparred. and that's fair enough.
to answer your question, then, no i don't believe it reflects badly on the style itself. only on that particular individual. and even then, it says he had a bad day. not necessarily that he was a bad practitioner.
it's very difficult to draw meaningful conclusions from one encounter.
stuart b.