I think you have a point. Trump could have brought up a number of things like sanctuary cities or the Clinton Foundation. Why he didn’t I’m not sure. However, Hillary came across as a sleazy politician, promising everything and delivering nothing. And Trump pointed that out many times. I think Trump may have really won this debate though his performance was poor, simply because he did not come across as a typical politician.
By not doing so, Trump didn't appear as the scary guy that the lamestream media and the Clinton campaign (yes, I repeated myself) portrayed him to be.
So, while Clinton may have won the debate on points -- Trump likely won the debate on votes.