Sounds fairly normal to me, the behavior you described is the same as when pressing the power button, on a lot of the older macs, pressing the case near a button sometimes presses it, for example, on my old MB, if I press to the right of my trackpad, the mouse button clicks. Nothing you should be too afraid of. Just treat that area as if it was the power button, unless you hold for a while on that area (as you would on a power button) it shouldn't cause too much trouble.