This part is important: “This engagement was undertaken in accordance with the International Standard on Related Services 4400 applicable to agreed-upon procedures engagements.”
Previous big4 here, GT most possibly only performed a stock count of gold and applied the formula provided by NEO team to reconcile the NNN amount, within the AUP.
Not really a big deal in terms of assurance as none is given in accordance with generally accepted account procedures in AUP projects. In practice, an AUP means “I perform the procedures we agreed on and nothing else, I don’t give assurance on anything as normally I do in other audit projects”.
I doubt they ever looked into ownership. You could have an AUP in which you have the company show up and leave without doing anything.
Edit: Read the full report, GT performed a stock count on gold, mathematical application of NNN formula and comparison of the amount to the blockchain. No big deal as mentioned but it’s good optics to have the “operations” audited by a company.