Except for a few nuances, I haven't found much in MoH to be particularly authentic. I know they were going for authentic rather than realistic, but I'm not certain what differentiates the two in their minds. Here are a few things that I noticed, which may fall into the category. However, overall, the experience felt much like every other recent modern combat game, except a little less "super warrior saving the world from an evil stereotype with a nuclear weapon" stuff. 
 
I'd also like to hear from those who are in a position to know better than myself. If you were in the military -- particularly afghanistan -- how do you feel this came across? What was authentic about it? What was realistic, about it? In particular, in ways that differentiate it from other previous shooters. What are some major lapses in authenticity? 
 

• One in the chamber. I liked that when you reloaded your weapon, it counted the round in your chamber. So you'd have 31, instead of 30. 
• Explosions. I liked that when bombs were dropped and buildings collapsed, the sky went dark and filled with dirt and smoke and debris in a way I haven't really experienced in other games, that I can recall. On the other hand, I hated the "environmental destruction". Shoot at a huge defensive boulder and huge chunks of it just vanish. 
• Audio. When one of the guys with you is talking over the headset, but is also in the room with you, he can be heard through both means. Not sure I've experienced that, before. Usually a game just plays his "over the headset" audio. 
• I liked that I was just playing dudes. Skilled, exceptional, special forces dudes, but just dudes. Sometimes over the top stories are exciting and fun, but I appreciate that they were trying for more of a "day in the life" experience, here. Even if I don't think they totally nailed that. 
• Importance of support. I'm just guessing, but I get the impression that the emphasis placed on the importance and timely value of support (air support, etc) is accurate...ish. I especially liked the moment, which I'll describe as loosely as possible as not to spoil for others, when you are in a thing and so certain that the end is coming and the odds are insurmountable -- and perhaps the next thing will be your own scripted death as a part of the story. . . and then the gunships come. Something about that struck me in a way events in similar games haven't. I think it's because they waited until the last moment to come to your aid so it was a bit of a surprise.

I think by authentic they meant that these kind of exact missions happen in real life with these guys and that nothing here is out of the range of possibility.

DICE has always been inaccurate about firearms. M1911's firing in double action, slides not locking back after the last shot has been fired, weapons that dont need to be cocked/charged after an empty mag reload, mirrored models that just look stupid because everything is in the wrong place, I can go on for hours. I really like DICE for their level design but I dont think they've delivered a single decent experience since BF2. BC2 was OK IMHO, singleplayer was horrible and the multiplayer was the same formula  you've been playing for years. But I really feel for Danger Close. Seeing that your character racks the slide back after a reload instead of using the slide release on a P226, Slapping the bolt on AR-15's after the gun's gone dry and a reload has occured and many different details make you really feel like your character actually has some personality in his movements. If only the game hadn't been rushed to be released before CoD: BO I think it would've been exceptionally well. They've spent the time they should've used to make a good game on creating details that don't really mean much when the whole experience isn't that great. I haven't played the SP yet but have watched vids from the game that pretty much cover the first day of the campaign and have participated in the beta on PC(Horrible bug filled-spawn killing camper fuckfest on the PC). Then again I really can't point out my finger and say that's a good game to any EA title that's been released in half a decade. I really don't know what they're doing in EA. They're not producing what we call "Games" that's for sure... 
 
Sorry about the messy text BTW, it's 5 in the morning and I've just used a fuckload of painkillers so I'm not really in the greatest mood right now.
 
Peace out. Hope to see some good stuff from Danger Close in the near future.

"I think by authentic they meant that these kind of exact missions happen in real life with these guys and that nothing here is out of the range of possibility. "

The environment looks like Afghanistan.

google wikipedia. this game is actually based on real events. it's not some creation. it's on real soldiers' life unlikely other FPS bull shit. 

Nothing is more authentic than Medal Of Honor.

" @scarletsnake: I think OP was referring more to the single player which was developed by Splash Damage...or was it Danger Close? Can't even remember the dev's name. "

The beards in this game were modeled after authentic beards used in service.

I'm still waiting for a realistic military shooter where during the first mission you take a stray bullet in the leg before spending a couple of weeks laid up in a field hospital then being flown home to spend a month or two hobbling around on crutches occasionally going to the supermarket late at night on the hunt for some cheap bacon.