Not only emergency vet fees, but the sitter is expected to pay any vet expense upfront:
5.3.5. pay any veterinary expenses up front and request the Pet Parent to reimburse you for all costs incurred
Having to pay for any vet fees upfront is putting quite the onus / financial responsibility on the sitter.
I agree as to having a discussion between HO and sitter regarding payment for vet care should be established. A sitter may not be able to afford vet care and a HO having an account established to pay vet costs certainly will take the financial burden off of the sitter.
5.3.6. immediately contact the Pet Parent in the event of any damage to property and get their approval for repair. If, in the event of an emergency, you are unable to contact the Pet Parent, you will pay for the repair of any damage caused, and request the Pet Parent reimburse you for all costs incurred (provided you have not caused the damage yourself);
If I damaged a HO’s property, I would pay and not expect to be reimbursed.
However, if the HO’s property is damaged beyond my control and I am expected to pay, I would not be happy about it—particularly if it is an astronomical amount.