I can't help noticing that whenever I read of or see videos of people crashing on a Zero due to the rear wheel spinning up, it always seems to be a DSR which has semi-offroad tyres (or semi-onroad tyres!). Those tyres just don't seem to have enough grip for road use when the road conditions are less than perfect. Perhaps the higher centre of gravity compared to an SR doesn't help either?
It reminds me of an event from my teenage days (a long time ago) when I was a passenger in my brother's car and we were following a guy riding an offroad bike, fitted with knobbly tyres, on wet roads (and it was raining). As the rider slowed to turn into a side road my brother said "He must be mad to be riding that bike on wet roads with those tyres, I bet he comes off when he turns", and as soon as had he finished talking the rider very slowly turned, at about walking pace with the bike almost vertical, and bang - in a blink of an eye the bike slammed him to the ground! Offroad tyres are not good for riding on wet tarmac roads!
I bought an SR back in June and I've only ridden it in the dry so far, and the rear has lost traction briefly on a few occasions when accelerating flat out in a straight line (with the bike upright so I didn't have any problems), but other than that the Pirelli sports road tyres seem to have plenty of grip. Those rare occasions were usually the result of a small bit of gravel in the road that I hadn't spotted or couldn't avoid, but the tyres quickly gripped again. I'm fairly sure that my bike wouldn't have crashed like that DSR did in the videos in previous replies. (Hopefully that isn't my "famous last words"!)