Contradiction with Mark 14:72
It immediately contradicts with the timing of Peter's realization mentioned in Mark 14:70.
Mark 14:72: And the second time the cock crew. And Peter called to mind the word that Jesus said unto him, Before the cock crow twice, thou shalt deny me thrice. And when he thought thereon, he wept. [when...: or, he wept abundantly, or, he began to weep]
Contradiction with Luke 22:56-57
Different description of Peter's denial when focus is on the maid.
Luke 22:56-57: But a certain maid beheld him as he sat by the fire, and earnestly looked upon him, and said, This man was also with him.
Contradiction with John 18:25-27
Offers a different sequence and context for Peter's denial of Jesus.
John 18:25-27: And Simon Peter stood and warmed himself. They said therefore unto him, Art not thou also [one] of his disciples? He denied [it], and said, I am not.
Contradiction with Matthew 26:73-74
Provides an alternative narrative on Peter's dialect betraying him.
Matthew 26:73-74: Then began he to curse and to swear, [saying], I know not the man. And immediately the cock crew.