it is your own job

When you make offer, your agent should tell you to use 7 to 10 days option. During the time, you should hire an inspecter to inspect the house.

If the agent did not tell you to use option, you can sure the agent. If your inspecter did not find those defect, the inspecter should take responsible.

In most case, it is hard to prove the sell KNOW the defect and did not tell you on seller's disclosure. If you can prove, the seller should take resposible and it is a crime to hide known defect.

In real estate transaction. The money paid to agent and professionals include insurance.