Can California MediCal come after a lawsuit for wrongful death to try and get paid back what they paid out in the underlying wrongful death action?

No, MediCal cannot seek reimbursement in a wrongful death action - only in survival actions. Special rules applies to MediCal and their reimbursement lien seeking powers.  I suspect this may have something to do with the fact that pain and suffering damages are altered in a wrongful death action - the suit is filed by the survivors of the person who was wrongfully killed and this affects how MediCal cannot get reimbursed on such legal actions.

Here is the law on this FAQ:

Fitch v. Select Products, 36 Cal.4th 812 (2005)  Although Medi-Cal is authorized to file suit against a third party liable for the death of a Medi-Cal beneficiary who received benefits, the controlling statutes do not authorize Medi-Cal to recover such benefits from the plaintiffs in the action for beneficiary's wrongful death. Medical expenses are not recoverable in a wrongful death action—only in a survival action.