Ars Technica reported on how a backwards S-Pen can permanently damage the Galaxy Note 5.
The right way to dock the S-Pen into the device is to slide the pointy end in first, but if you slide the blunt end in first, the S-Pen will get jammed in the device. The spring mechanism that holds the pen in will clamp down on the wrong end of the S-Pen and won’t let go. It is possible to wiggle the pen free from the spring’s hold, but when we tried it, the S-Pen detection features stopped working.
Normally on the Note 5, removing the S-Pen when the screen is off will launch a quick note taking app, and removing it when the screen is on will launch the radial S-Pen menu. After putting the S-Pen in backwards and wiggling it out, all of these features stopped working.
We can see that they put in a lot of thought into the design of the device.