Well, something to remember for Coil is that he isn't hacking the system. He's likely having Lisa just legitimately access it with stolen information via her power. He's not really burning anything he isn't prepared to lose and can easily replace. There is no system glitch to fix, or hole in the programming. Lisa logs in just like she normally does under an Admin account and discreetly shuffles the paperwork around. If caught, then Coil is likely prepared to have the finger for it pointed somewhere expendable.
Because that is a thing from Canon. Lisa showed that she was perfectly capable of using her power to lift accounts, passwords, the whole she-bang so she could get into PRT/Protectorate files on a whim.