not quite in that league, but i decided to do a Trailquest on the Isle of Wight many years ago. it had been a very wet winter and the day was marred by gale force winds. i got blown over, still clipped in and holding the bars as i crossed a field on a bridleway. later i was taking a 'shortcut' to the next checkpoint... i was the only one around and it didn't occur to me the reason why.
i turned a corner on the bridleway to find a large puddle - no problem. being clay based soil it was hard to see how deep the puddle was as it was just brown and gloopy. it was a pretty long puddle though, about 20ft at least. anyway... in i went. up to the tyre bead. oh well. up to and then past the rim. keep going. half way up the spokes. trouble. the clay was slowing me down and it was now so deep my feet were dipping in with each pedal rev, so i was trying to coast through.
soon the axles were about to get wet and the momentum had stopped. i lookde for a way to bale out. there was a fence to my right. for a brief moment i stayed there, held tight by the clay, but soon gravity was calling. i leaned over to the fence and thus started my fall. no problems, i'll grab the fence and hold myself up and drag the bike out.
it was around then i saw the glint. the glint of sun. sun on the barbs of the fence.
it was too late, i would fall on the fence anyway, so i grabbed it, embedding a barb into my palm and held myself there, slowly lowering myself down to the ground - firmly clipped into the bike.
the day ended with me riding with a flat front, having buckled the valve during a clumsy reinflation. i missed the train at Brockenhurst and whiled away the time 'til the next one by carving chunks of clay off the bike.
the next day i went and got a tetanus jab.