Anybody ever tried taking a normal in sunlight shot and another one while covering the LCD to verify this under-exposure issue?
No need to. The camera meter doesn't change once you take off the lens cap.
Try it yourself. Take the camera outside on a sunny day. Leave the lens cap on, have the full sun shine on the top LCD, take a meter reading. Shade the top LCD with your hand, take another reading; it'll be a stop or so different.
Now, take the lens cap off and try the same. Even if you're pointing at something dark in deep shade, the meter reading won't change.
Why? Because the meter is actually sensitive enough to get a reading in pitch dark, but it's a veeeeeeery noisy reading at those practically-nonexistent light levels. Noisy enough that the less-than-starlight leak through the LCD is able to alter the readings.
Think of it this way. You can light a candle at the far side of the field on a bright, sunny day, and you might not even be able to tell that it's lit. It certainly won't cast a shadow at that distance. Do the same thing in the middle of a moonless night and you'll have no trouble seeing the flame, and though you might not be able to see it cast a shadow, your camera can probably take a picture of the shadow.
I don't think there's any way to trigger the fault while using the camera (and its meter) within published specifications. Now, of course, people use their gear outside of the range of published specs all the time, and more power to them. And if Canon wants to demonstrate a bit of goodwill by helping those living over the edge, that's fantastic.
But pretty much everybody panicking or even whining about this is making a mountain out of a molehill when they live in the middle of a city where the only moles to be found are in the zoo a few hundred miles down the coast.