Now I'm not a smart guy but...
Why wouldn't Clyde have the entry within the warehouse that then leads to his secret tunnel rigged to explode if a code or some other trigger isn't deactivated?
Even a keyboard warrior like myself with no CIA experience and about as far from a think tank for them as the Earth is from the Milky Way would have some sort of plan like that - so I'd think that someone with Clyde's smarts would have something far better. To have no protection for his secret tunnel seems just sloppy given how intelligent this guy is meant to be.