Better said: poorly built low-spoke count wheel, what could possibly go wrong? This is just a bunch of silly boys who don't know WTF they're doing. The tri-geek with the wing bars wasn't dropping back, he was pulling left to attack the new leader. The silly 3rd boy had overlap on him when they went by the old leader. And this is no paceline, it's just a bunch of riders larking. The guy who went down did a good job of getting control back. He should have been fine. Unfortunately, his front wheel was a POS. His spokes broke when he touched wheels, not later. The broken spokes are the reason he went down. His front wheel locked up in the gravel from rubbing on his fork.

None of these guys knew what they were doing. The leader held his line in the middle of the road. The attacker wasn't using his aerobars. The tri-geek shouldn't have even been there. I don't ride near guys on wing bars. They can't shift without taking their hand off the brake. At least with clip-ons you have a normal road bike except when you're pulling or solo.

In a paceline, the front rider goes left and eases off about 1 mph. The line then pulls through on his right. Except on a wide shoulder, then the leader goes right so the line stays next to the fog line. In a rolling paceline the next rider pulls off as soon as his rear wheel clears the front wheel of the old leader. On a tandem, the stoker signals the captain, "Clear!" It takes practice.