Fortunately, or unfortunately depending on where you were sitting at the time, no one was hurt.. Blow up may be a bit exaggerated, the end caps that prevent the cleat from rotating failed over the course of 3 days-1 day of hard upwind sailing followed by 2 days of hard reaching. In the end the lower set of 3 blocks was no longer attached to the base and was riding at the top of the mainsail. Needless to say these problems made sheeting the main a b$tch and resulted in at least 3 capsizes.

I should mention that a replacement Ronstan lower block assembly was available to us, however the attachment point to the traveler was a whopping 3/16" stainless clevis pin, which I've bent on a Hobie 14 mainsheet system, never mind a 8:1 N20 mainsheet. In the end we used a friends Harken 10:1 system which worked flawlessly for the rest of the race.