On US military uniforms, the flag patch is usually worn backwards on the right sleeve. In the movie, the flag is displayed in the wrong orientation.
The vehicle that fires at Ernesto is a PT-76 amphibious tank (this is a 1950's recon tank from the former Soviet Union), not an APC.
Just before the APC/tank fires at Ernesto you can see cords going into the barrel of the main gun.
Just before the APC starts attacking the rebel base, a Blue Jay can be seen. Since 'Soldiers of Fortune' takes place in Eastern Europe, there should be no Blue Jays there, as Blue Jays are a North American species of bird.
During the opening credits a satellite zooms in on the region between Pakistan, Afghanistan, and Iran. Rugged mountainous terrain is revealed, but there is actually only desert in that area.
The latitude/longitude shown for the base camp, (43 00 7'0.004, 35 00 69'3399), is not a valid coordinate. If rounded to the nearest valid coordinate, it is a spot in the middle of the Black Sea.
When Haussman fires his hunting rifle from uphill to the raided rebel camp, you see him pulling back the "bolt" after the first shot, but that particular model is semiautomatic.