For problematic cases, I'm happy to explain the process that we envisage.
Essentially, the applicant would fill out the online application. Verifications would be done centrally through what we would call a centre here manned by CIC officers 24/7. If there were any indications of adverse information, the eTA would not be issued, but the client would then be directed to the nearest Canadian office to have an interview or an examination with a Canadian visa officer overseas. That officer would then complete the interview to determine whether an eTA should be issued. Essentially, they would have access to the resources and the supports that are normally available through CBSA and our Public Safety partners.