SQL & PL/SQL

We have a table of system logs that has a column called created_date. We also have a UI that displays these logs ordered by created_date. Sometimes, two rows have the exact same created_date down to the millisecond and are displayed in the UI in the wrong order. The suggestion was to order by primary key instead since the application uses an oracle sequence to insert records so the order of the primary key will be chronological. I felt this may be a bad idea as a best practice since the primary key should not be used to guarantee chronological order although in this particular application's case, since it is not a multi-threaded environment, it will work so we are proceeding with it.

The value for the created_date is NOT set at the database level (as sysdate) but rather by the application when it creates the object which is persisted by Hibernate. In a multi-threaded environment, thread A could create the object and then get blocked by thread B which is able to create the object and persist it with key N after which control returns to thread A it persists it with key N+1. In this scenario thread A has an earlier timestamp but a larger key so will be ordered before thread B which is in error.

I like to think of primary keys as solely something to be used for referential purposes at the database level rather than inferring application level meaning (like the larger the key the more recent the record etc.). What do you guys think? Am I being too rigorous in my views here? Or perhaps I am even mistaken in how I interpret this?