I think it depends how you understand the phrase "physical evidence" I think komponisto was using the phrase to mean physical evidence directly tying Knox et al. to the murder victim. Such as DNA, fingerprints, etc.

So I don't have a big problem with his characterization. As I mentioned in the thread on rudeness, the polite thing to do is to is to respond to the best reasonable interpretation of one's opponent's argument (while noting the imprecision).

(FWIW, I do believe that Knox et al. were probably involved in the murder but that's a separate issue.)