I don’t know why the writer says Patrick isn’t a saint. He is on the calendar and we observed his commemoration on 3/17. He has a “proper” reading and prayer in my breviary. It doesn’t get much more official than that.
There was no formal canonization process for Saints, as we have today, in this early period. A person just needed to be locally known as a godly Christian example to be regarded as a “Saint.”
If you look up other Celtic Christian notables, virtually all of them are called “Saints” and are folks generally we’ve never heard of (thought about St. Willibald recently, or raised a glass to St. Briget?) unless you’re an historian of Celtic Christianity.
Patrick is regarded as a Saint in the traditional sense...but, he went through no formal canonization (the 2 miracles, and other requirements to be approved of by Rome) which is what Driscoll was referring to.