Imagine doing something as simple as dropping into a prone firing position while bounding with another firing team or dismounting out of an MRAP and getting tangled in the five point harness which caused you to fall six feet on to your rifle. I've done both of these things resulting in zero damage to my rifle and EOTech while overseas, but that was not the case for a particular ACR and EOTech setup here Stateside.
This particular rifle and optic combo was simply dropped; due to carelessness, from a height of about five feet onto a covered concrete floor. The stock has broken clean off and the EOTech's window has cracked. As a testament to the EOTech's wherewithal you can still acquire the reticle; whether zero has been compromised, I couldn't tell you.