Contradiction with 1 Samuel 6:19
Contradicts the idea of seeing an angel being a positive experience, as the men of Beth-shemesh were struck down for looking into the ark.
1 Samuel 6:19: And he smote the men of Bethshemesh, because they had looked into the ark of the LORD, even he smote of the people fifty thousand and threescore and ten men: and the people lamented, because the LORD had smitten [many] of the people with a great slaughter.
Contradiction with Genesis 32:30
Jacob saw God face to face and his life was preserved, differing from the fear in Luke 2:9 due to God's presence.
Genesis 32:30: And Jacob called the name of the place Peniel: for I have seen God face to face, and my life is preserved. [Peniel: that is, The face of God]
Contradiction with Exodus 33:20
God tells Moses that no one can see His face and live, in contrast to Luke 2:9 where seeing the angel does not lead to death.
Exodus 33:20: And he said, Thou canst not see my face: for there shall no man see me, and live.
Contradiction with Judges 13:22
Manoah feared he would die after seeing an angel, unlike the shepherds who were reassured in Luke 2:9.
Judges 13:22: And Manoah said unto his wife, We shall surely die, because we have seen God.
Contradiction with Revelation 1:17
John falls as though dead seeing a heavenly figure, contrasting with the shepherds' fear being allayed in Luke 2:9.
Revelation 1:17: And when I saw him, I fell at his feet as dead. And he laid his right hand upon me, saying unto me, Fear not; I am the first and the last:
Contradiction with Numbers 22:31
Balaam bows to an angel in reverence, an action absent among the shepherds in Luke 2:9.
Numbers 22:31: Then the LORD opened the eyes of Balaam, and he saw the angel of the LORD standing in the way, and his sword drawn in his hand: and he bowed down his head, and fell flat on his face. [fell...: or, bowed himself]