The pizza delivery person isn't acting as your agent and representative.
If you work for a company, and break something serious for a client - it's not you who gets sued, it's your company because you were acting on their behalf.
These lawyers were hired by Oracle to conduct legal matters on Oracle's behalf - if they win the case, it's not the lawyers who take home the prize - it's Oracle. Conversely, if they lose, it's not the lawyers who pay the penalty - it's Oracle.
So, it's not out of the real of possibility that Oracle will be fined or penalized in some way.
If they win, Oracle gets the rewards. If they lose, Oracle gets the penalties. If they screw up, Oracle gets the fines.
There is a wide gap between paying for a service and hiring an employee to work for the company.
Meanwhile, you would be legally exposed to lawsuit to reclaim that half million dollars in damages.
Where'd you get that idea? https://en.wikipedia.org/wiki/Respondeat_superior
It might not be your fault, but the question of "who made the mistake?" doesn't really enter into it.
I don't think it's clear that Oracle is in the same position wrt their lawyers as a pizza customer is wrt the delivery guy, though.