Once again I don't understand the point you're trying to make. When discussing the accuracy or otherwise of the statements in the PJ files a poster wrote that "Rebelo admitted there could be mistakes".
Is that a fact or an opinion? The answer is simple. A cite quoting Rebelo is needed to confirm it is a fact. If no cite can be produced it's an opinion being posted as if it were a fact.
No it could be a simple mistake, he may have accidentally made an error or deliberately made an error. If it is worded as a fact a cite needs to be producible if asked. I feel opinion needs to be made clear that it is opinion e.g . saying something referring to yourself e.g. I think, or IMO.
An example of a mistake is missing out the word "not", a mistake I make too often e.g. ""Rebelo admitted there could be mistakes" becomes "Rebelo admitted there could not be mistakes". (Not such a good example as both appear as reported facts, as "admitted" implies there is a statement to that effect.)