I have a couple possible ideas:
1. Given the KERS problems, Vettel may have been getting talked through some sort of shut down procedure, but he didn't seem to be looking into the cockpit too much so this is maybe a bit off.
OR
2. Vettel was being given the PR blab over the radio and being told not to let on about a possible problem with the car and pretend everything is all sushine and fart in the interviews.
Either that or the kay was stuck in the ignition.
