From the vid if you look the dryer is in compartments which are offset like a drill bit so when they open the far end it "screws" the paintballs out and doesnt stop spinning
there will be like a corckscrew in it so that they end up flowing out of the end, the tumble drier would never stop if you watch the video the dryer is still spinning when she pours them out
And if you look at the balls as they drop out of the machine they are still very soft, so just like a ball left out in the rain for a bit if you dropped it it wouldn't break. Just bounce like a heavy balloon