You should have explored a bit, might be cake down there

I heard it's a lie

So you'd hold down all 3 buttons at once, or press them in a specific sequence, or...?

When you did this, did the floor indicator show anything different?

And where (what country) was this?

It was three floor buttons at the same time. I cannot recall what the floor indicator said, but the elevator was quite old and might not have even had one.

This was at the University of Calgary, engineering buildings (circa 2000)

Interesting! Thanks very much for the info. Now to find the other lifts out there with controllers from around the same time period that operate similarly... :)

IIRC it felt like a late 70s/early 80s elevator. No manual controls, but the first style of automated elevators. The buildings were completed in the late 60s. I assume that these were probably installed at the beginning.