Both the Surface and the TypeCover should have enough ESD protection that ESDs should not cause any lasting damage, but a restart due to ESD is a whole different ballgame, and it's much more difficult to protect against.
Having all the latest FW is not necessarily the best in this case because the January FW fixes were probably just rollbacks of the December 'fixes'.
I had this happen to me a few days ago, and in that instance it happened twice in one day. I did a hard reset, as I was having another issue, and its probably coincidence but it hasn't happened since.
As much as I love this device when it's ON, I've never been so frustrated at were what I thought to be mundane things. C'mon MS, this is 2014. Putting your computer to sleep shouldn't be Russian roulette, now on top of that I got to worry about reattaching the cover.
Agreed...I actually think the type cover is the source of many of the bugs that people are seeing (whether it's the device driver or a hardware issue). Since I've returned mine (waiting for power cover -- hopefully it doesn't suck), many of the sleep/power related bugs have stopped occurring.