Those other things and the intervening medium

Read in the Sydney Herald Morning web site, in the article "Credibility concerns prompt calls for interpreting training" :

"We can train them to do well those other things that do have an impact on the outcome".

The article refers to court interpreting.

"'Most barristers would form the view that a jury is likely to lose the impact of a witness it there's an intervening medium such as an interpreter.''

A catalogue of those other things, that is besides the words output, requires a big shift from language considerations into gestures, tone, speed, attitude and more, and the position, presence of the intervening medium. The attitudes of the intervening medium is also heavily culturally built and biased. It's just a feeling, nothing quantified or deeply thought about. In Japan, the communication dynamics in liaison interpreting is determined to an extend I assume to be large by the nationality of the interpreter and the rapport of nationality between the interpreter and her direct clients. It is by no means limited to Japan. But what is clear here at least is that Japanese at large are ill at ease and suspicious with an interpreter who is not Japanese. When they have a choice, they dismiss the non-Japanese interpreter. This single element defines the market. And when it is the foreign clients who come with their own interpreter, the nationality of that intervening medium is a major element that is to define the dynamics of interactions. Has anyone written about this?

Addendum:

Also read this corollary article : New research reveals the importance of accurate court interpreting

How these reflections should be extended to interpretation outside the court, into all the possible situations of liaison (community) interpreting? I am especially concerned here with business interpreting where there are outcomes and issues and consequences at stake too, with various degrees of severity.