Although I was tangentially involved in the aforementioned incident, I'm not sure what level the change came from or what the process is but it was an extremely broad order--at least Marine Corps-wide, and possibly for all units in theather (excluding SOCOM/JSOC, I assume). So pretty high up. The incident made some pretty big waves. As far as the turnaround time, it was quick, within a few days I believe.

It's worth noting that this was one of many incremental changes. When I started that deployment in 2009, snipers were going out in 5-man teams. The team that got hit actually did technically consist of 8 men (as was already the SOP), but they were split into two four-man elements that took different positions about a kilometer apart. The mandate going forward was that all 8 team members had to be within earshot of each other at all times. It was the latest of many orders in the trend of ratcheting up firepower at the cost of concealability.