They were baptized with the Holy Spirit on the Day of Pentecost. They were given special gifts. And guided by the Holy Spirit in their teachings. When you say they were mistaken you're saying the Holy.Spirit misguided them. The Apostle Paul would say when he was just giving his opinion and not something given to him by the Holy Spirit. You are expressing your personal views when you claim they are mistaken.I do believe all human writers are capable of mistakes, even religious writers.
When I am not convinced of something written in the Bible, it is true the writer may be mistaken, but it is equally true that I may be mistaken as well.
They were ordinary men. God chose ordinary men.