I think it's unlikely that Adam would be liable for having accepted an inflated valuation. Courts typically give management pretty wide latitude to make business decisions as along as they can give some plausible explanation. It's called the "business judgment rule" in corporate law and gives the company quite a bit of deference[0]. It derives from Delaware General Corporate Law § 141(a), then gets carved out through case law.

That said, there are a few ways to overcome it. Self-dealing is one way, assuming Adam didn't disclose the transactions. Fraud would be another.

All this stuff is pretty fact-specific. We can guess, but there's a lot we won't know until it gets litigated.

[0] https://en.wikipedia.org/wiki/Business_judgment_rule