Perfectly annealed glass will break if you drop it on the floor. If you drop it and it DOESN'T break, you were just lucky. If you drop it on the floor and it DOES break, then you have to clean up broken glass. It's still glass; stress it beyond its capacity and it breaks. This goes for both soft glass and boro.
Back when I first started working with glass, I was showing a friend some boro things I'd done. "Look!" I said, "you can drop it on the floor and it won't break!" So I dropped it on the floor and it broke. Cured me of that particular idea pretty quickly. Learn from my mistakes!
