Behaviour of Locked Objects

Hi everyone here,

I have one question regarding the behaviour of the locked objects in the Illustrator. Let me explain in different scenario, and there is one scenario which is I am unable to understand. 

Scenario 1: Locked Object inside the layer.

When any object is locked which is just inside the layer, we cannot select the that object, which seems correct and also we cannot move it.

Scenario 2: Locked object inside the group.

When there is a locked object inside the group, and I tried to move the group, every item inside the group moves except the locked one. This seems to be correct as well.

Scenario 3: Locked Object inside the layer, and move artboard.

In this scenario, when I try to move the artboard, Illustrator gives an alert saying "Any hidden or locked objects in the artboard will not be moved". Which makes sense and object does not move after moving the artboard.

Scenario 4: Locked objects inside the group, and move artboard.

Here when I try to move the artboard, I got the same alert message as in Scenario 3, but object moved with the artboard. How and why? Is it some thing that I am not aware of.

Attach are the screen shots for this scenario.

Artboard at (0,0), selected rectangle is at (72,72)

Second screen shot, an alert message that I received.

Artboard moved to (72,72) and rectangle also changes its position (144.41,72) even when it is locked.