My commentary would be that the IAA representative is incorrect about the FAA 3rd class medical: the FAA issues it with no restrictions on validity outside of the USA, i.e. there is no chance of FAA action as a result, while recognizing that foreign law can add any additional restriction for operations within that specific foreign country.
One level below the FAA 3rd class medical is Basic Med, the new FAA certification, and it is FAA restricted in validity to operations within the USA.
Other than that, it sounds like the author is trying to be helpful in what has under EU regulation become a hopelessly incompetent shambles.