Actually, it's not so much fuel starvation as over fuelling. The fuel is regualted by the jet needle which is connected to a float in the float chamber. In normal operation, the float sits on the fuel in the float chamber and regulates the flow into the venturi. Under negative conditions, the float follows the fuel and ends up at the wrong end of the float chamber, thus opening the jet fully allowing unmetered fuel to flow into the venturi causing a ''rich cut''.
If you look closely, you should see a puff of black smoke as the engine picks up as the excess fuel in burnt off. Also, the engine picks up immediately which wouldn't be the case if it was due to starvation.