In this post, technical writer Milan Davidovic that contributing to wikis can help novices build skills and a portfolio. And he offers a simple roadmap for doing that effectively.
In the absence of safety concerns, I think that accuracy must win. Thus, as the information curator, you have a responsibility to correct inaccurate information. If the inaccuracy is truly dangerous, you may need to edit the post directly. Make sure that you disclosure what you've done with brackets.