You raise some interesting questions there, but the very fact there was an apology and a Resolution making a "confession" is amazing in itself - a stark contrast to the GB of today (and recent years)!
Can anyone seriously imagine any member of the current GB standing up and reading a Resolution seeking Jehovah's forgiveness for any errors within the organisation? Or printing such in a Watchtower article (or today's equivalent - making a statement from behind that fancy desk at JW HQ on a monthly broadcast?)
That JW vs JW clip shows that it's not just that someone may "err", but what compounds the error is when they stubbornly refuse to change their way, and then even if forced to change later, they will deflect away from the need for any apology or admission of guilt to phrases like "it's a refinement", and worse, tacitly blame God for it by saying things like "Jehovah was guiding one way previously, but now he has directed us differently".
It reminds me of the very same way in which the leaders of the Biblical nation of Israel often behaved, and God called them "stiff-necked" and "hard-hearted", and indicated that they themselves were often to blame for the suffering of their own people and for the attacks on them carried out by other nations, as He withdrew His protection due to their disobedience and attitude.
Likewise today, much of the ridicule JWs endure, and the "persecution" at the hands of governments, is because of policies the GB choose to enforce, many of which are not scripturally required.
For example, while not taking up arms is a Christian stance, there is no need to refuse alternatives to military service, yet in many cases the GB has insisted brothers and sisters not even do civilian duties. This has brought Witnesses in many countries into unnecessary conflict with governments and law courts over decades.
And now, much of the suspicion and negativity aimed at Witnesses is due to the secrecy of the GB regarding sexual offences, financial irregularities and other crimes and misdemeanours which they have allowed to build up over the years, when they could and should have lanced these boils of corruption and sin ages ago, made public confession and cleaned up the organisation.
Yet still they double down on being God's only representative on earth, and His only "faithful and discreet" servant, who must be listened to and obeyed without question.