Ask HN: Our Project Partner Is Resigning – Future Liability Question

I have been working on a SaaS product / website for 13 months in my spare time (evenings and weekends) with a friend, we have finished the product and are now ready to launch but due to health issues and fundamental differences about the future of the product my partner wants to resign from the project and hand over all equity / have nothing to do with the project anymore.

The domain name is the only real asset that he controls & before transferring it over to me and relinquishing future claims over IP / ownership, he wants me to sign a legal document which releases him from all liability which he could be exposed to from launching the website, the document states that if he ever got sued that I would need to cover all of his legal costs, without a limit, which seems odd.

We have only operated through an informal partnership (we both signed a letter which defined our roles & equity ownership %'s).

I wanted to ask others who have done this before, is this normal? Is there anything else that I should do in this situation?

Thank you in advance!