You need a frame work to address what is an ethical practice. Principles guide these practices: honesty and objectivity.
Identifying yourself as a journalist achieves honesty. But under what circumstances is it necessary to identify yourself? When are you a journalist? Are you always a journalist? Are you only a journalist when you have a recorder in your hand?
Are hidden tape recorders ethical if the story protects the public? Is it necessary to explain to someone that their opinion is on the record? Does protection against authority warrant violating an agreement with a member of authority?
It is difficult to answer these questions. The speaker continued to pose questions without a true answer. His only guiding advice was put the audience first. That may mean put the truth first. It may not. And protecting the public is just another ambiguous responsibility.