Encountered a near carbon copy replay of BentMikeys Vauxhall Arches/truck incident this morning. Heading towards Deptford roundabout there where 3 Tip-up trucks in front. 2 of them managed to clear the roundabout, the third had to stop to give way. Myself and 3 other cyclists stopped behind the truck. Or so I thought. One of them decided to go up the left hand side of the truck just as it started to move off. I shouted "Don't go up there!", but he carried on. The truck moved to the left to clear the roundabout with the result that the cyclist had to do an emergency stop and near jump of his bike. I heard a "shoot" from one of the others behind me. As the truck cleared I said to the cyclist "That's how cyclists are killed". We got to the next set of the traffic lights and one of the other cyclists said to me he though the chap was a goner. The cyclist who was nearly crushed then came between us, shouted at me "Thanks for your concern..but...*something I couldn't hear*" then proceeded to RLJ and turn left.