If you watch the slow-mo replay, the fuel rig mechanics never made any motions to pull-out the nozzle from Jenson's car when the lollipop was abruptly raised. They were still fueling Jenson's car that's why a mechanic got drenched with petrol when the nozzle was torn-off after Button sped away. Looks like a human-error gaffe to me by the lollipop man, rather than the nozzle failing to disengage and screwing the lollipop man's pre-emptive timing action.
With Schumacher's defensive driving technique, Renault realized that there was no way Alonso can get past that Ferrari in Imola, so they quickly changed strategy and decided to make it a "battle of the pit crew" instead. In fact, I think that strategy made the final laps of the race more exciting to watch on TV rather than watch Alonso tailing the Farrari hopelessly and they go to the pits at the same time. It was exciting to see whether Schumi will come out of the pits just in time to block Alonso again. And that was exactly what happened. It made me jump to my seat.
