When Walter Harriman is interviewed, the name tag on his uniform reads "Davis."
A seasoned Air Force colonel wouldn't fire at something metallic at close range and risk a ricochet killing a member of his team.
Colonel Rundell is out of uniform. His mustache is out of regulation. Male Air Force members - enlisted and commissioned - are allowed to have mustaches but the mustache is not allowed to continue past the vermilion of the lips. No colonel would ever be caught so far out of regulations.
When researching the alien probe, Major Carter states "SG-13 really kicked the crap out of this thing." Later when requesting backup Colonel Dixon identifies his team as SG-9. (Actually, Dixon identifies himself as SG-niner, which seems to be shorthand for the commander of the SG team. It's akin to Admiral Adama identifying himself as Galactica Actual when talking to vipers or the fleet. In a number of episodes, O'Neill identifies himself as SG-1-niner, particularly when there are other SG teams nearby, and similarly refers to other SG team leaders as SG-[whatever]-niner. Since Hammond was talking to Dixon and presumably knew the team of which he was the leader, Dixon did not need to repeat the full team identifier.)