The purchase contract is set up with "active" contingency removals.What that means is that all contingencies remain until they are removed in writing. If a party to the transaction is not performing, the other side must issue a Notice to Perform. Issuing this Notice to Perform give the other party two business days to remove the contingency in writing, or the issuing party may cancel.
It's important to be cautious whenever you are thinking about cancelling a contract. Depending on the circumstance, you may wish to speak with your attorney first.