Usually Auditee feels comfortable in asking questions. They reckon Auditors as experienced and masters who can advice them for improvements.. I personally keep them with me.. and reply during lunch /tea breaks..without breaking ethical etiquates and codes..Above all WE ARE ALL HUMANS .
My experience as an auditor and being audited, is that discussion and guidance on ways to improve by Q & A will get the client thinking in the right direction and quite often get them to answer their own questions.
I am not against providing information and suggestions however I prefer to Q&A approach to get the client thinking and analysing and providing prompting or questions on the way to an answer.
I agree whole heartedly, "conflict of interest" should be dealt with in the "Code of Conduct" for an auditor.
Actually Auditee is asking question for their improvement and as a audit when we log an observation, auditee expect a suggestion.
To me, as long as there is no commercial interest involved we should suggest/guide auditee for improvement.