It says "The private key for the Subject Address is in the possession of the FBI". How they got hold of the private key is the crux of the matter.
screenshot saved on hdd? https://www.bloomberg.com/opinion/a...fbi-down-a-hot-wallet-trail-to-bitcoin-ransom
They hacked their billing system. The company could have still delivered oil if they wanted to, but decided to screw the customers, nobody gets freebies. Then the whole system collapsed and people had to line up for gas. So it was more on the company then on the hackers. They are usually careful to stay under the radar and not to anger the federal government. At this time the plan backfired and they even apologized for the hack.