Hi @Philip O'Rourke ,
Thank you posting query in Microsoft Q&A Platform.
Usually, When we have primary key or Unique key constrains we should see error while loading duplicate values. But in your case, you are saying its not happening with oracle. I am checking with internal team more on this and get back with updates.
There is no way to see SQL getting used behind the scenes of copy activity and I don't think we can enable or disable some behavior if there is no such option available inside Copy activity GUI.
SQL server don't have Direct path load for loading bulk data. Instead in SQL server Bulk Copy Program (BCP) for loading bulk data.