If the pin came out, it's because the roll-pin is broken. That only happens when either the saddles get banged out, or the spiders have welded to the crosspin and spun it
I suppose you could weld it up, but I would take it apart and fix or replace whatever it takes. I keep rebuilt spares around, and swap them in as I wear them out or they break. That way you can also adjust the preload on the clutches.