Contradiction with Acts 9:23
Explains that Saul stayed certain days with the disciples after his conversion, not immediately afterwards as implied in Acts 9:19.
Acts 9:23: And after that many days were fulfilled, the Jews took counsel to kill him:
Contradiction with Galatians 1:17
Paul states he did not go to Jerusalem immediately after his conversion but instead went to Arabia, which differs from the immediate integration with disciples in Acts 9:19.
Galatians 1:17: Neither went I up to Jerusalem to them which were apostles before me; but I went into Arabia, and returned again unto Damascus.
Contradiction with Acts 22:17-18
Suggests that Paul's acceptance by the disciples was not instantaneous, contradicting the impression from Acts 9:19.
Acts 22:17-18: And it came to pass, that, when I was come again to Jerusalem, even while I prayed in the temple, I was in a trance;
Contradiction with 2 Corinthians 11:32-33
Indicates that Paul's time in Damascus included persecution, not just fellowship with the disciples as Acts 9:19 might imply.
2 Corinthians 11:32-33: In Damascus the governor under Aretas the king kept the city of the Damascenes with a garrison, desirous to apprehend me: