Players have 24 hours to request a retcon of a scene that does not involve PC death. That's it. The longer things go, the more problems are caused by a retcon. Secondly, staff MUST inform all PC's involved that a retcon investigation is underway. RP dealing with that situation should be placed on hold until the matter is resolved. It is unfair to other players not involved in the original scene that they also end up having RP retconned because things continued to progress.
Generally these will be resolved within 48 hours of Godstaff receiving the information. It does take time to review logs, talk to the staff in question and sort out what can sometimes be very convoluted messes.
Retcon requests should be sent to your Sphere Wizard, the plot runner be they PrP Runner or Staffer, and Godstaff.