The lance is retracted and Eva lurches forward. A moment later, red fluid gushes out.
Reichu: Note how it's "red fluid", not "blood"… At this point, the script is playing up to the notion that the audience initially believes — and rightfully so — that the Eva is a robot. By not calling it "blood," there are no organic connotations; after all, robots bleed red fluid all the time, right? ;;P
Sharp-kun: Anyone who's watched Go Nagai's super robot series (most recently Mazinkaiser: Death! Ankou Daishogun!) will be very familiar with robots "bleeding".
Reichu: Now, how did I know you were going to mention that? ;;>
Mr. Tines: At this point one might still be thinking hydraulic fluid under pressure (and you'd need it for a system like that). But with later data, that no longer washes.
Reichu: I find it odd that there is not blood on Sachiel's lance when he retracts it, considering the amount that spouts out afterwards. It's interesting that EVA-01 bleeds at all, actually. Being as the lance is amplified by energy, I would presume that it is rather hot; ergo, might any injury inflicted by it be automatically sealed by cautery? (I remember my sister using this as an argument for why light saber duels are relatively bloodless.)
HeWhoPostsStuff: Further, would the Eva's blood be under such pressure so as to spurt out in fountain-esque fashion like that, rather than flowing from it, as with most wounds? Probably just done for stylistic reasons…
Reichu: This is actually an interesting difference between the anime and manga; Sadamoto's Evas bleed "normally". Perhaps we need to look no further than the Laws of Anime for the real reason:
#18: Law of Hemoglobin Capacity
The human body contains over 12 gallons of blood, sometimes more, under high pressure.
And the Evas, of course, are just really large, strange humans, so…
Hexon.Arq: An Eva that spewed red silly string from its head would have been a hell of a thing to market based on this scene. Of course, if they don't already make that, it's only a matter of time.
Reichu: Strangely enough, there is actually a glitch in Renewal here! (You didn't expect perfection, did you?) Consult the Original vs. Renewal page for more details.
Hexon.Arq: I did notice that glitch. It completely ruined my year.
Dr. Nick: Oh dear. Just wait till I get my Gainax quality control rant started in episode #12.
