Weather Sealing is a Gimmick.

Protecting against dew and frost poses very different engineering problems from protecting against the ingress of low-pressure liquid water and dust particles.

Consider this: when you have a weather sealed zoom lens on a weather sealed camera, most such lenses aren't internal zoom. Rather, they have to telescope their exterior bodies in order to change focal length--which means air pressure has to equalize. If there wasn't anywhere for the air inside the lens to go, you wouldn't be able to zoom the lens. Sometimes the air pressure can be corrected through gaps in the lens body itself, but that doesn't always work (tolerances tend to be tighter on weather protected lenses and we need to be able to zoom fast when we need to).

So every interchangeable lens camera, including weather sealed cameras, has to have a provision for air pressure equalization. Ken Rockwell's camera reviews actually go as far as to mention "eyeblow", the tendency of air to come out noticeably through the viewfinder when you zoom a lens rapidly (in some cameras it comes out in other places).

Now let's consider the problem of dew: Dew means the air is supersaturated with water, and as it gets cooler, the water can no longer remain in solution and it precipitates out. Frost is the same, but below the freezing point. The problem with dew is that the the same air is inside the camera as is outside, which means condensation can occur inside the camera if the temperature drops below the dewpoint. The camera internals have the advantage of being warmer than the ambient air while the camera is operating, but that wouldn't always be enough to get the electronics above the dewpoint.

Also worth remembering that water itself is nonconductive. What makes water conduct electricity is impurities; dust motes, dissolved compounds, etc. As dew is precipitating straight out of the air, it's going to be much purer than rainwater, let alone seawater, and so will much less likely to short circuit electronics. So I think the OP did not present a useful example in order to critique weather sealing in general.