Ask HN: How to deal with an employee that won't share code?

TLDR: I am being asked to audit a project but the person who created it won't share their code.

This employee, lets call her Ava, was hired to work on a project. She worked at this place for about 11 months. In that time, she created a SaaS product and showed demos to the employer, lets call him Max.

Max is not very code savvy, although he has a background in theoretical cpsc but his knowledge about dev tools is very limited. He doesn't know anything about CI/CD, git etc.

Max asked me to come and look at some of Ava's code. I said sure, why not. This is where the problem begins and I have no clue how to deal with it.

Ava has shared small portions of the code, not the entire code base. Just a few backend ORM classes/entities, basic stuff, which is not the meat/bones.

Ava refuses to share more of the code, and keeps kicking the can down the road. Random excuses, pulling shit here there, trying to fool Max by telling him all the code is on AWS etc. For the longest time he thought that the AWS resources were source code.

So, my question is how would you deal with Ava? Max wants to pursue legal means and sit down with a lawyer.

I want to avoid this route and want to know if there are any other methods of appeasement we can follow before the legal route. The lawyer route will take a long time, and the product needs to be released in 6 months.