Continuity mistake: Grimes gets handed a death letter and he holds it up. Camera changes and his arm and the letter are not in sight, which they should be at that angle. (00:29:00)
Continuity mistake: When Randy Shugart and Gary Gordon arrive to defend the downed chopper, Shugart is shooting his rifle as a right-hander, but in one short sequence as they're pulling Mike Durant to cover he is shooting as a left-hander. The shot has obviously been reversed as the bolt of the M14 and the height adjustment knob on the aim point optic are on the wrong side of the rifle. (01:29:00)
Suggested correction: You can see him change shoulders as he goes back into the building.
The mistake is valid. He's shooting with the rifle against his right shoulder and you can see the flag patch on his right shoulder. In the next shot, after the guy is pulled out, the rifle is against his left shoulder and he turns, he doesn't change shoulders as the rifle is still against his left shoulder after he turns. However, there is no longer a flag patch on his right shoulder, meaning the shot was flipped as indicated.
Continuity mistake: When Blackburn is reporting for duty, he asks what it's like. Grimes then puts his hands out, palm down. Camera changes and his fists are now clenched with no time to clench them. (00:11:30)
Other mistake: During Mike Durant's capture the helicopter circling overhead that broadcasts "Mike Durant we won't leave you behind!" is the voice of Tom Sizemore who plays Col. McKnight - it even says so in close captioning." Col. McKnight was in the streets of Mogadishu engaged in battle at that time. (01:44:45)
Factual error: In the movie the first Black Hawk helicopter (Super 6-1) gets shot down and just so happens to crash in a large four-way intersection. In the actual battle, Super 6-1 crashed in a narrow alleyway. (00:49:45)