In the investigation related to Mar-a-Lago, the Justice Department is seeking to pierce attorney-client privilege relating to several bits of testimony and discovery items they're seeking from Trump's attorney, Evan Corcoran. Such a move isn't necessarily unprecedented, but it is extraordinary.
Legal Eagle had a piece on this noting that while this move is extraordinary, it's becoming less extraordinary when it concerns lawyers for Trump. Per Legal Eagle, it seems that Corcoran did not wholly trust the information being given to him by his client and engaged in the notable move of recording his conversations. Thus, Corcoran can probably provide testimony which will indicate that he said things that weren't true, but did not knowingly lie because the basis for the information he conveyed was based on the information his client had provided to him. Presumably, because he lacked mens rea, he could not be culpable.
However, this lack of mens rea may not be applicable to other attorneys whom have worked for Trump. Presuming a court permits piercing the attorney-client privilege for those attorneys, could those attorneys continue to impede the investigation by asserting their 5th amendment rights?