4.He has been busy with his SMs during his interview, which in the interviewer's aspect could connotate the sickness of the poser and the improbability of intercoursing with bona fides.
5.Whenever possible "Freephone" or similar facilities should be provided so that Respondents can check the Researcher's bona fides without cost to themselves.
6.Knotty details are skimmed over without sacrificing the crucial points, though at one stage Mr White guides the reader through a few lines of low-level computer code, perhaps to reassure the technically minded of his bona fides.