If setup correctly, it should't LOL assuming you have proper drainage, your main tank should never overflow past the overflow lines. Sometimes, if a large turbo for example crawls into one of the overflow tubes, it could slow down the flow to the sump, and cause a flood.
My 45g has a hob overflow. Even if it loses siphon, my tank and sump's water levels are designed to never overflow. The worst that will happen is that my sump will dry up and my pump will break from pumping dry. But whether my pump cuts off or my siphon breaks, no flood as long as I don't go past my lines.