Yes, of course the qualifications and medical are facts. But it was speculation that the pilot might have been under qualified or not medically fit that made the investigating team check that out. I realise this seems pedantic and I chose the quals and medical because it's so obvious. You cannot investigate without speculation.
Moving on the radar track: The report draws upon the radar track to support the conclusions. Once introduced as evidence, the AAIB should have considered whether that evidence is accurate. We know that no measurement system is 100% accurate so there must be tolerances. Maybe the AAIB did consider those. Maybe they didn't. But they should have mentioned it in the report.
I'm not arguing that there was, necessarily, any significant error in the radar track. I'm casting doubt about the competence and diligence of the AAIB team that issued an accident report.