I can't find the audit itself; it may not be released yet, but it was announced in 2018, and this link mentions the possibility of demanding a refund:

"California's high-speed rail project is facing an audit from the U.S. Department of Transportation's as costs continue to climb.

The inspector general's audit, announced Thursday, will examine the Federal Railroad Administration's oversight of nearly $3.5 billion in federal grant money awarded to the project.

Bringing in the feds raises the possibility of real trouble – as in potential demands for refunding of misspent federal funds – and may well dash dreams that the feds will step in and fund the tens of billions of dollars that would be necessary to actually build more of the line "from nowhere to nowhere" currently under construction in the Central Valley."

americanthinker.com/blog/2018/04/californias_high_speed_rail_fiasco_getting_a_federal_inspector_general_audit.html

*The ABC link cited in the article about the audit has been pulled.