How is the guard stabbed in EoE

[Javik]

There's a scene in EoE in which SEELE initiates the attack on Nerv headquarters. In one scene a soldier sneaks behind one of the Nerv guards, stabs him and then they open the gates. The thing is, how did he sneak unnoticed if the gates were close. Wouldn't the guard hear the gate behind him opening up? Or did he somehow enter from the side? Then how did he not notice him if he's standing so close to the wall? Here are two pictures I've made depicting the scene:
The Guard being stabbed

The view behind him:

[CommanderFish]

I've always thought that the guy was a double-agent.
a.k.a. he worked for both the NERV guard personnel as well as the JSDF. That is obviously just a fanwank though. I think the point of the stabbing was ultimately to get a cool-looking shot, which in my opinion, it was.

[Reichu]

Looks like there's just enough space behind the guard for the soldier to ninja/MGS that shit and sneak behind him.

[Javik]

Well, but how did he get behind him in the first place. I mean, wouldn't he have to hop through all the terminals on the way?

[FreakyFilmFan4ever]

^ The guard's face suggests that he's wondering the same thing.

Guard: "The fuck...?"

Man in Black: *STAB* "Shhh... Just let it happen.

[Glor]

Guard: "The fuck...?"

Man in Black: *STAB* "Shhh... Just let it happen.

*gently caresses his cheek*

I think the point of the stabbing was ultimately to get a cool-looking shot,

Whaaaat? Anno doing something just because it looks cool? Impossible. There must be some deeper meaning behind it...

[FreakyFilmFan4ever]

Honestly, I think it was done simply because it was a quick and simple shot. I often find myself wondering similar things as I'm writing my own scripts and projects. "Wait, how would this character have gotten from here to there in the first place anyway?" You try to write in an explanation, but quickly realize that it's distracting from the main story and you've already got 12 other things than need to be established before we can get into the juicy part of the story. So instead of explaining something, you just state that something simply happened that way in the script and hope the confidence of the scene makes it so no one questions how it happened.

EoE had a ton of story progression to go through after the invasion, and I'd rather the film use two simple shots to establish that minimal plot point rather than dedicate a whole scene explaining how they invaded. Air is all about getting Shinji into Unit 01 and getting Rei to Lilith. Everything else, how ever important it might have been to the narrative, was still either tangental or in support of those two narrative goals. By the end of Love is Destructive, very few people are thinking "Wait, how did that dude get behind the guard?"

[mammaluser]

He could have dropped from the ceiling or as other people in this thread suggested he could have been a double agent.