It was clearly stated that the pax and baggage were offoladed due to payload issues, and IMO, this might have had the potential to cause a problem.
If there were 15 pax, baggage and cargo removed, someone must have made an error somewhere, which is why an MOR was mentioned.
Captain then announced that ground staff had made a mistake and had erroneously boarded all passengers when they should have offloaded 15 passengers (and some luggage and cargo) due to payload issues.