From Reuters:

To conceal the transfers of customer funds to Alameda, Wang, a former Google software developer, built a backdoor in FTX's book-keeping software, the people said.

Bankman-Fried often told employees tasked with monitoring the company's financials that the book-keeping system was "the ultimate source of truth" about the company's accounts, two of the people said. But the backdoor, known only to his most trusted lieutenants, allowed Alameda to withdraw crypto deposits without triggering internal red flags, they said.

This also sounds more like an explicit backdoor built into a system, but not totally conclusive.

But the funds that Alameda had spent were no longer easily available, so the company used FTX customer funds to make the payments. Besides her and Mr. Bankman-Fried, she said, two other people knew about the arrangement: Mr. Singh and Mr. Wang.

Keeping this arrangement from the rest of Alameda / FTX, including legal and compliance, strongly implies they knew it was fraudulent.

Agree with your point on (2) that it could technically mean admin DB access.

While SBF presents himself here as incompetent rather than malicious and fraudulent, his account here contradicts previous reporting in (at least) two nontrivial ways.

• It was reported that Caroline Ellison, CEO of Alameda, admitted to Alameda employees that a deliberate decision was made to dip into FTX customer funds to cover Alameda's insolvency.
• It was reported that a backdoor had been implemented into FTX's internal accounting systems to allow SBF to alter financial records without triggering alerts.