If npn transistor switch is saturated, does base get galvanically connected to emitter?
So I did some reasearches, and found this answer:

The reason, why current does not flow from collector into base when transistor is opened, is in physical properties of the transistor. Since emiter is doped more heavily then collector, and base are made very thin, electrons are flying directly from emiter into collector, and only around 1% recombines in base. So no reverse base current exist.