After reading what Cashill had to say about TWA 800, I decided that he had little credibility. Cashill's job is peddling conspiracy theories. The fact that he claims to be an expert on so many of them would seem to indicate that he cannot be the greatest expert on each one, and also that he will always tend to slant things in the direction of excitement rather than truth. I read a bunch of what he had to say about the ghost-writing of Obama's books but did not feel that he succeeded in making his case. To top it off he is a creationist. And he writes for World Net Daily. (These are both bad signs to me.)
Somehow Cashill manages to project an image that is in contrast to what people expect a nut to look and sound like. He probably makes some valid points but where are you supposed to draw the line?