You probably start by saying 'Hey I think this might not be fully compliant?' And if your boss comes back with anything other than a reasonable justification, you know there's something going on, and you should flag it higher up/leave that place
The market maker account is different from a regular customer account so the reflected balance will show the in-flight liabilities. Don't worry about it, the number is just an artifact.
Probably was an admin with code reviews exempted for admins and just merged to master