Originally Posted by MysticBlue
When it is upshifting from a lower gear to a higher gear, under normal cirucmstances, the higher gear is alread selected for the second clutch and input shaft. As the first clutch starts to disengage, the second clutch is already starting to engage. We're talking milliseconds here so I don't see that as undo wear on the clutches. That's what clutches are for. So, depending on the aggresivness of the software, there absolutely can be a shift where torque applied to the wheels never actually drops all the way to zero.
For the sake of argument, lets say there was a malfuction and both clutches fully engaged. They would both be turning in the same direction, just 1500 rpm (give or take) different. One or both clutches would then be slipping that much and yes, wear out very quickly, but the wheels aren't going to lock up.
Guys, this issue has been beaten to death, and if you do a search on DCT shift times, you'll find some interesting discussions. Look here for instance: