Your statement means nothing. Look up how much money Stanford receives through NSF, NIH, DoD, etc.

The webpages for most of the graduate studies/research departments seem to indicate that some level of public funding is expected/necessary for at least some students and researchers at Stanford. An example[1]:

The department has limited funding available for MS and PhD students, which is awarded at the time of admissions by the program coordinator. Prospective students are encouraged to seek funding from external sources such as the NSF GFRP or AHRQ Dissertation Awards, and/or for Stanford-based funding such as fellowships available through the VPGE Office.

[1] https://med.stanford.edu/epidemiology-dept/education/graduat...

Which likely gets most of its research funds from government grants.

Concretely - over 70% come from the federal government:

https://facts.stanford.edu/research/

Not spending any public funds?

Private university doesn't mean that public grant money isn't used in research grants.

And the alleged misconduct happened before he joined the university.

Many of the research grants are funded from public tax dollars