I learned that the hard way and had to reimburse the tenant 14 months of utility bills.

You expended resources and time which has cost you actual dollars and that without the certificates and the leases you will be forced to reprice your offer assuming all of the tenants live there rent free or back out and seek reimbursement for your costs due to the seller withholding material facts.However, I am making a REALLY big assumption here based on what you posted.

And if you're filing for rent court/eviction, she is also reimbursing you for that (or she should be!).

Some cities (I have experience with Castro Valley providing a monetary credit for a full sewer line replacement) have monies set aside and will reimburse you a small % upon completion of the job.In Alameda County sewer lines need to be inspected upon sale of a home (In most cities, not the whole county) and the responsibility to fix the line coming off of the city main line (Generally located in the middle, or middle-ish of the road) falls on the owner of the home if the line is faulty.

Get your employer to pay for it or change jobs to a place that will reimburse.  

The buyer has sent a demand letter and is threatening to sue if I do not reimburse them for a new sewer line they installed about a month after the closing.

You should also send something to the agent certified with return receipt as well as his sponsoring broker and let him know that you have sent this to the Seller as motivation for both parties (e.g. reimburse my earnest money by XX date or I will be pursuing this in small claims court in the amount of $XXX times 3 as mentioned in the contract Paragraph 1, Section 3A blah blah blah and you will be responsible for my attorneys fees as well) - have an attorney help you with the language to make sure it meets your needs since many states are different.  

It's not a nice gesture when they knew they were going to be reimbursed.

He is reimbursing me each month for all the utilities, water, electric, and Comcast.  

But someone has to pay for this, and it would likely be the buyer since the seller hasn't any money, and if the liens turn out to be real the deal is dead and the buyer is out his money (unless he gets a contract for full reimbursement if the liens are real, unlikely the seller would sign).