EOTech Issue...

For those who own EOTech sights. This has been an ongoing 'complaint' for at least a year.

http://soldiersystems.net/2015/09/30/ussocom-issues-safety-use-message-eotech-enhanced-combat-optical-sights-plus-goings/

So it wasn't you, there really is an issue with the sights due to temp changes, and parallax error.