The "incorrect state" being talked about is the IP prefix being misregistered in ARIN's database.
The "hijacking" happened later, when the IP prefix was announced via BGP by the registrant who it was incorrectly assigned to. Those are two different events.
It was re-allocated to the new/wrong ARIN customer for seven days before they started announcing it, at which point the OP detected the issue. Prior to that their prefix was routing to them just fine, just without RPKI protection.
The "hijacking" happened later, when the IP prefix was announced via BGP by the registrant who it was incorrectly assigned to. Those are two different events.