I had a case like this once. Corporation enters into contract with my client. Contract is signed by corporate insiders and has a warranty of agency clause. Client provides services. Corporation stiffs him. I write... hey you owe my client money. Corporation, thinking they're being smart, responds X and Y didn't have authority to enter into the contract, so it's void. Me... fine, instead of just suing you, I'll sue you and your officers and let the court figure out who's liable.