I am never sure how to approach an appeal where a factual error by the MHT has materially affected their decision. As this is not an error of law I never know how to frame an appeal where the MHT have simply misunderstood the evidence - which seems to be happening more frequently with remote hearings.e.g The tribunal think the patient is still exhibiting symptoms because they mishear the RCs evidence.
I approach an appeal on misinterpretation of evidence in exactly the same way as I would an error of law. Lay out the background, explain the decision being challenged, detail the grounds and state that the tribunal decision is an error of law in that the tribunal have incorrectly understood evidence and an error of fact due to the misunderstanding. If the video conference was the cause that is the basis for both law and fact.
hope this helps.