I’ve been having this problem on a regular basis. Whenever vvvv exits, the VLC node causes a crash (“vvvv.exe stopped working”), but only if playback is active. A rather unsexy solution I found is to delay vvvv shutdown for a moment while setting the “play” pin to zero. This works at least for alt + F4, but not when Windows shutdown causes vvvv to close.
vvvv 34.2 x64
VLC 2.2.4
EDIT: It works fine with 34.2 x32.