isn’t it 7 judges? Justice Goss decided Evans evidence should stand but did advise jury they could choose to disregard it. Then the 3 judges of the first appeal decided the same. And then the second appeal were a further 3 judges that were different to the first 3.The role of the expert witnesses sounds like they are suggesting Dewi Evans wasn't up to it and it should go back to appeal courts. However four judges have already decided Dewi Evans's evidence should stand. How many appeal court judges are they? Do they want them all to listen to their argument until they find one that agrees with them?
Your last question is an absolute yes. Even if they wanted best of 3, they already lost!