Grrrr, bone constraint limit causing huge trouble. what am I doing wrong ?

Hello,

Here is a file i am playing with.
I am more or less following a tutorial here:

The wanted behaviour of my file is showed at 28:00 on the link

But in my version the orientation is not the same: my rig is orientated upright, perpendicular to the Z and not the X axis.
There is a pair of bones, namely Cover front and Cover back that make problems.

If you add a limit rotation constraint in the world space so that the bones are limited to movements betwwen 3 O’clock and 9 O’clock, that goes bonkers about 6 O’clock

No matter what, I cannot reproduced what’s done in the tutorial !

Can you help ???

Armature problem.blend (575 KB)

EDIT: even more horrible: in edit mode take the whole armature and rotate 180 around Z-axis.
And there it’ll work. Why doesn’t it work when not rotated then ???

Oh I hate these kinds of things…