I like where they're going with this!

And then I just stole someone else's work and called it my own! But catchy saying, huh?

I'm guessing things like antihistamines suppress the production of this mucus? What would happen if this process was turned off completely? Is this mucus produced in response to something physically in the nose that it's trying to flush out? I could understand allergens and such as those are physical particles but what about when you have a cold/flu? What's actually being flushed out? I just got over a flu where I was blowing out tremendous amounts of liquid so I'd love to know what my nose thought it was flushing out, aside from what it was producing itself.

I'd dare to say it's a little of both since I thought he said it was still raining but didn't continue to leak.

The water was likely running from another location then dripping through the spot you saw. When you pushed the screwdriver through, it may have created a small lip of soft material (drywall?) around the hole that now diverts the water around the hole and somewhere else. Picture it as the lip around a crater or an ant hole created by the upward pressure of soft, wet material by the screwdriver. The water drained quickly at first because it was above the 'rim' but once it went below, it started going to the next low point on your ceiling. That's my thought anyways.