Contradiction with Mark 9:38
This verse similarly records John forbidding someone casting out demons in Jesus' name, but both Mark 9:38 and Luke 9:49 share the same event, thus they don't directly contradict each other.
Mark 9:38: And John answered him, saying, Master, we saw one casting out devils in thy name, and he followeth not us: and we forbad him, because he followeth not us.
Paradox #1
The contradiction or conflict in Luke 9:49 could arise from the idea of exclusivity versus inclusivity. The passage may suggest that someone doing good work or performing actions in Jesus’ name should be accepted even if they are not part of the immediate group of followers. This can conflict with the human tendency to be wary or exclusive towards outsiders who don’t belong to one's own group or community. There is a tension between accepting good deeds regardless of source and maintaining group identity.