I have found the twists aren't very forgiving when dropped. I had one roll off the counter like yours and it died, and another I dropped only a short distance and it broke the button. That's 2 twists in less than a month! I wish they'd start making Kgo vv's. They've always been great batteries IMO and they can take a beating too!
I have some original 900 mah ego batteries, and those things were just short of bulletproof. This was back when they came in 2 choices, black or stainless. They're actually so old, that almost all of the black finish had worn off, so I have stripped it of the rest and now have a couple original nice stainless egos