A blown up PSU will not necessarily damage other components. Just 2 weeks ago, a small company brought 8 desktops to our repair shop, all with blown PSU's due to an overcurrent in the local area. After replacing the part, the systems were back to fully functional, no other parts were damaged.

In such a situation a number of components can fry inside the PSU, typically the large capacitor and the fuses are the first to go.

You got lucky there.
When my Power Supply blew up it killed 1 ram, the graphic card and the mainboard battery

It also can mark build quality of Seasonic - even if it really blows up you still have a chance to be ok.