Sola, it is absolutely not technically going "beyond what is written" to use non-human 'witnesses'. Exodus 22:13 makes it clear that non-human evidence can count as a witness.
This principle was used by Solomon in his well known "baby-splitting" decision. It was a case in which two women both testified that the same child was theirs. Two witnesses did not exist - it was a case of one woman's word against another, analogous to a modern day situation where it's a case of one person's allegation (eg, a horrified mother catching a paedophile 'red-handed' molesting her child but there was no second eyewitness) against the word of a lying paedophile. But Solomon used the women's ACTIONS as a "witness" to arbitrate the tie and establish a second "witness" to agree with the verbal testimony of one against the other. And that decision was called a wise one by the Scriptures.
Jesus also said that his miracles were testimony (John 5:36). Also, a woman's reaction to the bitter waters was used as evidence against her unfaithfulness to her husband in Numbers 5.
Since the great majority of paedophile crimes are never witnessed by a second human eyewitness, and since the Society is setting the bar so high by requiring two witnesses for sexual crimes against children, the Watchtower Society MUST make it mandatory for all elders to ALWAYS notify the superior authorities of EVERY allegation, whether the state law requires them to or not, and irrespective of whether the parents have or not. The superior authorities act as Jehovah's "minister" and "executioner" against evildoers (Romans 13), and so the elders should feel no compunction whatsoever about reporting all allegations to the secular authorities who act as "ministers" for God in a judicial sense, whether the law requires them to or not.
Without this potential second witness being invoked, the great majority of victims cannot possibly produce a second eyewitness. It is clearly an impossibly onerous standard of evidence to require two literal eyewitnesses for sexual crimes against children (and arguably all scriptures that refer to the 'two witness' rule applied to allegations of crimes against adults only, not children). But if the elders are compelled to always report all allegations to the secular authorities and not hide behind so-called "ecclesiastical privilege", the victim who cannot produce a second eyewitness, which is practically every victim, is therefore given full opportunity to obtain the second "witness" of the secular authorities.
Without compulsory reporting by the elders of all allegations no matter what, the elders are leaving it to the whim and vagaries of parents who may be tempted to not report the allegation because of misplaced concern about not exposing the organisation and congregation to public shame, perhaps caused by some over-zealous and misinformed elder or other member of the congregation who have whispered in the parents ears that to go to the police might drag the congregation and Jehovah's name through the mud, so perhaps it's just better to "leave it in Jehovah's hand" and not take your brother to court. This very thing has happened countless times to the great harm of countless innocent children.
What your personal "belief" is about what Jehovah minds or not is irrelevant, unless you are a mystic.