Actually, in the two group rides I've on the road since deciding to get back into it, I've stacked both times!!!!

Firstly was into the back of Hitchy when he decided to stop for a couple of Jap tourists at the stop lights in St.Kilda (I mean really, who actually stops of pedestrians? Loose all streetwise roadie points immediately). Secondly was with some old mates up in the Dandenongs on a loop I'd never done before. We approached a roundabout, I went straight, they turned right.

Landed in the emergency room after that with a nice chainring induced gash in my leg.

Sorry to hear about your stack matagi. Heal fast.