SoldierSystems.net posted up details on the settlement between L-3 and the US Government over problems with Eotech optics.
Read SoldierSystems article here.
Some of the important notes are that Eotech knew about issues back even in 2006. Various issues include changing zeros in temperature shifts, parallax error in cold temperatures, moisture entering sights and dimming them. Also that Eotech knew of these issues and did not disclose them to the government.