My predictions came true again

While these predictions are absurdly vague, I'd like to shine some light on the "and/or" debate.

If you say "The door was red and/or blue." you are implying one of the following to be true of the door:
-The door was red.
-OR-
-The door was blue.
-OR-
-The door was red and blue.

Another example- "The boy was wearing a hat and/or glasses."
-The boy was wearing a hat.
-OR-
-The boy was wearing glasses.
-OR-
The boy was wearing a hat and glasses.

By saying something like "an unprecedented and/or natural event" the OP implied one of the following to be true of the event:
-The event will be unprecedented.
-OR-
-The event will be natural.
-OR-
-The event will be unprecedented and natural.

So far no one has explained the use of and/or correctly, and I hope these examples might help clarify for those in doubt.

ETA: I misread the original line, which was "unprecedented and/or large natural event"
I think to acheive the desired effect, a hypen between large and natural eould suffice.

Grammar Nazi rehab isn't as effective as they said it would be..........