Hopefully that dangerous lunatic spends the rest of his life in prison. There's a good discussion on the All Chile expat board that touches on just how demented the guy is.
As for the political situation, a consensus seems to be emerging right now in Chile, which is that there will be a new constitution. Piñera is in a bind - replacing his cabinet of family and friends with more seasoned operators makes him stronger on the surface - widened base of support - but clearly they're not as invested in his rule as the family and friends were. You see that already - members of his own party are joining the opposition to criticize the plan to draft a new constitution as insufficiently collaborative. Makes sense - the constitution has to pass by plebiscite, and the process will damage the government even more if the thing is rejected at the ballot box. So, while Piñera resigning is still some distance off, and it's a good guess that if an election were held today he could win again, there's a real risk that the constitutional convention gets away from him/his government.
The most obvious implication for Argentina seems to be that if Fernandez was considering continuing/reimposing austerity a few weeks ago, he's probably not feeling so great about that idea now. And in that, with how quickly and broadly the situation took shape in Chile, in retrospect, it's hard not to see Macri as having made the wise call in not administering shock treatment when he first came to power.
