Is it possible for an applicant to pass a pre-employment polygraph despite the examiner's attempt for a post-poly interview?
Yes. Sometimes polygraphers will fish for admissions, even if the polygraph charts are not scored as "deception indicated." And with certain agencies, in particular the CIA and NSA, it is commonplace for examinees to be told they're "having problems," to be interrogated and badgered for admissions, and then to be invited back for one or two follow-up sessions.
Thank you for your reply. This polygraph test was with the FBI. The examiner left the interview room for approximately 10 minutes. Upon his return, he indicated that he consulted with multiple on-site polygraphers for quality control, which they all agreed on DI.
The FBI is not in the habit of bluffing when telling applicants that they've failed the polygraph. I'm sorry to say it, but I expect you'll be receiving a pro forma rejection notice soon.