When showing the gang tied up and in nooses Lawson says they have double aught wire around their necks. Wire gauges get bigger as the numbers get smaller with 00 gauge being .365 inches in diameter. What is around their necks looks to be about 18 gauge which would strangle them and would make it hard to cut them down but is too thick to cut their necks like a garotte.
Angel's language skills: This episode establishes that Angel is relatively fluent in German; previous episodes have shown that he speaks Russian, Romanian, Spanish, Korean, and Chinese (all at least on a conversational level) as well -- thus, Angel can communicate in at least seven human languages.
SS man wearing black uniform: The SS man, a Obersturmbannführer (Lieutenant Colonel) is wearing a black uniform aboard the sub in 1943. A common Hollywood mistake: After the beginning of WW2 in September 1939, the regular SS began wearing grey uniforms. The black uniforms were only worn on special occasions, like public state funerals but not during regular duty.
In "The Trial", Angel briefly entertains the idea of turning the dying Darla, with the theory that perhaps she'll keep her soul since he has one. This logic doesn't fly thanks to the existance of Lawson.
Lawson: We all need a reason to live, even if we're dead. Mom, apple pie, the Stars and Stripes... that was good enough for me. Until I met you. Then I had this whole creature-of-the-night thing going for me -- the joy of destruction and death -- and I embraced it. I did all the terrible things a monster does. Murdered women and children, tortured fathers and husbands just to hear them scream, and through it all, I felt nothing. Sixty years of blood drying in my throat like ashes. So what do you think? Is it me, Chief, or does everyone you sired feel this way?
Spike: I wanna be called Captain. I mean hell, I did eat him.
Angel: Check the torpedoes before I stuff you in a tube and send you for a swim, "Captain."
Spike: Really ought to do something about security. They'll let anybody in here, won't they? Fred gave me the Cliff Notes. So sailor boy finally came back for a yo-ho-ho, did he?
Angel: Finally came back...
Spike: Took him long enough... I know revenge is a dish best served cold but his must've been frozen solid.
Angel: I don't think that's what he was after.
Spike: No? Then what was he looking for?
Angel: A reason.
Lawson: Come on chief, give me a mission.
(Angel stakes him)
Angel: We need them. I'm not getting trapped at the bottom of the sea!
Spike: And I'm not getting experimented on by his government!
Spike: Sneaky bastards, the SS. Don't ever go to a "free virgin blood party". Turns out, it's probably a trap.
Angel: You were captured at a "free virgin blood party"?
Spike: I know. Who'd'a thought?
Angel: You're a Nazi.
Spike: What? Oh! No, I just ate one.
Spike: Bloody brilliant. Turn the poor sod to save the ship, then make him dash for dry land before Mr. Sunlight scorches him a new one. You're still a dick.
Angel: Yeah. I am. (Moves aside, giving Spike a clear path to the ladder)
Nostroyev: I will tear you open and play "Coachman, Spare Your Horses" on the lute of your entrails!
Lawson: Aren't you going to ask how I got in here?
Angel: Nah. You'd be amazed how many people break into this building on a regular basis.
Angel: Spike's not in the S.S. He just likes wearing the jacket.
This episode is the first (and last) time we see Spike with black hair.
Lawson is the only vampire Angel sired while having a soul.
The name "Prince of Lies" originated in the Buffy the Vampire Slayer episode "Lies My Parents Told Me" (7x17), which was also written by Drew Goddard. In the episode, Drusilla suggests nicknames for a freshly sired Spike, one of the names being "Lucien, Prince of Lies." However, director David Fury cut it out, and Drew was excited to finally be able to use the name in this episode.
WB used the promo title "1943" for this episode.
Spike: Yeah let me know how that works out for you, Popeye.
Popeye the Sailor is a famous comic strip character. He gains strength by eating spinach.
Hodge: He's some sort of super soldier like Steve Rogers, or Captain America.
Steve Rogers aka Captain America was a comic book hero introduced during World War II. He was a genetically altered super soldier who fought the likes of Nazis, Japanese and other threats to America during the war.