IIRC correctly region protection on computers is actually a two-step process.
First is the hardware itself. The drive's region can be changed five times before permanently locking to the last set region; unless tempered with before that happens. However, even making the drive itself region free still has (most) software checking for the region of the disc. Apparently VLC doesn't care, but otherwise there are software solutions (mostly not free) that can circumvent the software to complain a "wrongly set" DVD drive.