Accents, Powerpoint, Picture - The Return of Silence

Around 2/3 months back, I had this interesting conversation during a presentation...

Presenter: .....to wrap up, this new service will deliverable a better ROI for our customer. any questions, thoughts...

Uber: I having trouble understanding how you can attribute the growth of our customer's sales solely to our service.

Presenter: Well as you can see in slide X, the rationale is explained

Uber: Yes I can see that, but there are other factors too that help to drive sales. If the customer ask can we back up our numbers?

Presenter: I do not think you understand nothing is that black and white

Uber: If nothing is black and white how is this presentation so black and white in terms of attributing success to us.

Presenter: You are misunderstanding me. Maybe it is the language..

Uber: I understand. Furthermore I speak with an accent but I do not hear with one.

I also wondered is it the accent that causes miscommunication or is it the lack of clearly explanation (oration skills). With the advent of Power Point, the orator no longer replies on speech but on visual to communicate effectively. But though a picture speaks a thousand words, I believe that words with picture often communicate more than just picture. Actually less picture/charts with more words are the best. If that is not the case, wouldn't Hollywood be making silent movies still...?