Rotational issues with bones in blender

So I have an armature in blender that behaves kinda weird. When I rotate a bone around one axis lets say the Z. axis it adds little values like 0.000014 to the X and a different value like 0.000017 to the Y axis. I really dont know how this could happen. I rotate with the global axis so there shouldnt be any issues. I will provide the file below. The first bone to be selected in the file is an example of a weird behaving bone. Rotate on the Z axis and see the values go mad.Generation_Zero_Inspired_Robot_ITERATION 1blend.blend (3.2 MB)

A quick update I have started to remake the armature and it happend again. Its quite weird is it just that rotating bones in blender is inprecise? How to properly recreate problem: Open blender add a bone then change the rotation to XYZ Euler rotate the bone 90 degrees so its laying flat and rotate it along a single axis. There will small adjustments made to the other axis even though you are rotating the bone another direction. I have filled a bug report here: