When team leads reviewed the spreadsheet to sign off on the payments, they didn't see the row, and there was no rollup showing total payments or anything else that would've helped them catch the malicious activity. The transactions were uploaded to a tool allowing asset transfers via CSV, and the required six out of nine multisig members approved the transaction.
PeopleDAO have reported that they're working with various security researchers to track the funds, and have reported the theft to the FBI and FTC.