We had a long debate about the pronunciation of Greek a few months ago, where I made a brief list of complaints about the article linked to (forum thread). The scholarship is abysmal.
The problem with this “we can’t know for sure” argument for me is that the author himself doesn’t believe it. This is an all too common sophistic dodge in arguments - for your opponent’s views adopt an evidential requirement which is impossible to meet, take on a radical epistemological skepticism. Then, when you make your arguments, state that of course the evidence is crystal clear. In this case his own arguments arre full of blunders of the most basic sort, for example I just noticed this additional one by chance:
The waw had the sound of /w/, as did digamma have the sound /w/. The evidence shows the exact opposite of the point he’s claiming to make.
On the subject of pitch accent he questions it somewhat, but says he doesn’t have time to treat it in detail. (Then goes into a long discussion too long to reproduce here!). He does point out that the accenting could have involved both stress and pitch. I think that is an important point.
I’m not sure anyone studying ancient pronunciation denies this.
I find that when I raise the pitch of a syllable it also ends up being more strongly stressed. Its almost impossible for me not to do that, in fact. But I’m a native speaker of English. I’d be interested to know if native speakers of other languages find this to be the case for them too.
We usually speak of English having a stress accent. It does, but there is a pitch component as well.