I see your point, but i would not say it is 50/50 either way. There is a 90% chance the system is passive.
Body work should be rigid, so the pipe cannot be squeezed. When the car is in Yaw, it shouldn't have a bearing on the signal pipe.
What shu said or didn't say, is mention of him trying to control the F duct when it's malfunctioning. Don't you find it weird it would be active, yet he never mentions troubleshooting it with his wrist or knee?
All other drivers who had problems with their duct, never complained of erratic behavior, and they always mention their part on the control end.
What I am hoping for is that someone show where the pipe is in this system. We've seen it for every team running an F duct but Mercedes.
Secondly i tried visualizing a pipe running up the end plate, but the end plate is probably 5mm thick; there's no way air would run through that without stagnating from boundary layer friction and back pressure.
As it is we don't even know how this Mercedes F duct works. It's a funny looking hole with god knows what is happening inside that wing.
I would like to hear F1-eng's opinion on this system. He seemed to have disappeared, but he was a staunch Mercedes supporter and possible team engineer; by the looks of things.