They'll do that. The actual moral of the story is to have your hand on the forend wood whilst opening.
I've learned that ejectors can be plenty sharp too, especially on the Superposed. I like to catch shells for reloading, and if you cover the ejectors with the palm of your hand and let them pop, they can make you bleed.
Rule # 3, never put your thumb inside the ejection port. Nothing is quite so guaranteed to cause uncomfort as an extractor through the thumb. It even interferes with holding your favorite beverage after the shoot.
