That's where his authority came from. The people were astounded by his authority more than his expertise. Jesus had no authority ex officio because he had no officio , no status or position or post. His authority came out of his own being, from within, from the person he was in relation to others. To be sure the truth has an authority of its own.
Facts are indisputable.
But facts can be used cruelly. You sure have gotten fat since the last time I saw you. It may be true, but it isn't healing or helpful, nor is it likely to inspire diet and exercise. Facts help if they are used in service to love. And facts about God are not so unequivocal.