Devonai, I was an SF augmetee, too, after 9/11. That was a fun week of training. Did you guys get to use any 40mm?
Aside from the M4 burst training, I also got trained on the M249 and the M2.
My issue M4 in Iraq was Safe-Semi-Burst, never did fire it in anything but semi.
We were taught trigger control, too, like everyone else. But some guys who aren't really accustomed to shooting, who are in a stressful situation for the first time, like their first enemy contact, a bit of panic can set in and full auto is as dangerous to the guys on their left and right as it is to the enemy. I had a guy dump half a mag trying to clear a non-existent jam on his weapon. He ditched it for his side arm until he ran it dry. When he went back to his rifle, training kicked in and he turned it from Safe to Semi and re-engaged. Yeah, his weapon didn't operate and he SPORTS the hell out of it, all because the safety was engaged.
The guy was an activated reservist with 13 years total time in service, 10 of which was on active duty US Army. He wasn't an 11B, so he didn't have anywhere near the level of familiarization. Of that real one and only fire fight I had, that was one of the biggest things that stood out and stuck in my memory.