Yeah, this thread pretty much boils down to peer evals. Let me give you a story. I got cellulitis in about week 3. Bed rest until my foot wasn't the size and shape of a football. First round of peer evals, mine were garbage. ALL of my scores other were in the top of the platoon and I've been in combat/highly deployed and handled myself as such, but it didn't matter. The "spear evals" reflected the sentiment toward the broke dick that lie in the rack and staired at the ceiling while they were out doing day IMC and SULE I. One difference though was the evals from the guys in my immediate area (my fire team) who REALLY knew me. It was all those other guys that just saw me as they ran in the back hatch and didn't know me yet who were ripping me. By the end, I had them squared away, but some never came around. May God help them because those were the conceited prima donnas who only do well in initial training ad then flounder when they get to the fleet where they actually have to think more than be loud and strong. I saw the same exact thing after enlisted boot camp.
1) First impression is KEY. If you can go the first 3 weeks with pretty much no mistakes, then nobody will be aiming for you when you do suck. The staff is too busy working on putting out the ones that have already identified themselves.
2) PERCEPTION IS REALITY. This canot be overstated. No matter how good you think you are, and how good you really are, how you are perceived in the quick judgment of your staff and peers is how you have performed whether it's in line with reality or not.
In the end, I'm not sure cut-throat is the exact word I would use in the sense that boot camp is cut throat. There, any recruit will throw any recruit under the bus at any time, any place to be better and stay alive. This includes diming others out, hitting each other, and stealing other recruits junk among other things. Those things pretty much don't happen at OCS. The candidates have a lot more to lose and are in a different mindset. You can expect to get a lot of open support from other candidates as long as you show an effort. If you find that you're behind and nobody is helping you, that's a bad sign.