When Sydney is picked up by Jack after the robbery, he is driving a mid 1960s Ford Zodiac police car in full livery - similar to the type used in the popular '60s police drama Z Cars. Why he should have access to a 40 year old police car, and why the real police arriving on the scene don't think it rather odd is never explained.
Goof: When Sydney stabbed Tamazaki with the sword, it went through his body but didn't penetrate the shirt on his back. Surely a sword so sharp would cut easily through a thin cotton shirt.
The guys new codenames at APO are as follows:
Sydney - Phoenix (because she rose from the ashes)
Vaughn - Shotgun
Nadia - Evergreen
Dixon - Outrigger
Jack - Raptor
Marshall - Merlin
Kicking off the operation in the train in Belarus, Vaughn says to Sydney "Horoshie siski." That's "Nice boobs" in Russian.
The train station shown in this episode is the Union station in Los Angeles.
While discussing the files that Sydney recovered, the writers manage to ignore every piece of evidence from the finale of season 3.
-Lauren's shouting "We're all pawns in the same game! The only difference is that I know who controls me."
-It's dated 1975, whereas the events that Sydney describes would have happened sometime past season 2.
-Sydney's NAME is on the cover, right next to "subject".
They seem to have been heading in the direction that Jack was the one in charge of the Covenant, and was using them as part of some sinister project involving Sydney, but wrote themselves into a corner and changed it.
What happened to Sark this episode is almost exactly what happened to him in Season 2 finale; from being jailed to getting his face broken by Vaughn.
Sydney's full name is revealed to be Sydney Anne Bristow.
Number 47: The initiation date of Project SAB47 is 04/17/75 (Sydney's birthday).
Number 47: On the same document there other references, such as "NO. 938 JB/47" and "176847."
Number 47: On the document that Sydney read in the end was a name for the project "S.A.B. 47 Project."
Number 47: (hidden and reversed) Hank Foster says that Sydney was logged in at the safe-house where Nadia was being held at 7.22 p.m. (2+2=4; =74).
When Lauren points the gun at Sydney, she tells Vaughn "if you love her, you'll put the gun down". This same situation also happened in "Blowback," except that it was Sark who was pointing the gun.
When Vaughn uses the key to Jack's storage shed he grabs a rifle with a scope, Vaughn takes off the cap on the scope and then looks through it, however it would be impossible to see any thing because he didn't take off the second cap at the other end of it.
As Vaughn is escaping the hospital he pulls the folded firehose from its storage case. The next shot shows a nicely rolled hose falling down the stairwell.
When Sydney took the clip from Katya, there was no bullet chambered. Even if she left the clip in there would have been no bullet fired.
If you remove a full ammunition cartridge from a gun and hand it to someone, the weight will give away that the gun is empty.
EMTs wouldn't move someone stabbed in the back and suffering from a punctured lung, on their back on a gurney. Yet that's how they move Vaughn when they bring him in.
We have every reason to believe that Sark hacked into the CIA security feed when Lauren was infiltrating the rotunda. When on a view of the feed on Sark's laptop you can see the point where Lauren takes her Sydney mask off, meaning if the CIA has all of the feed there would be proof that it was Lauren and not Sydney who stole the equation.
The CIA investigators probably already knew the one inside rotunda wasn't Sydney, otherwise, they would have taken more severe actions than just questioning her. Their main suspicion stemmed from Lauren and Sark knowing Sydney wasn't in the facility, thus pulling off their fake Sydney infiltration; they wanted to know why she was conveniently away during the attack.
Marshall noted that CIA paid him very well, though less than one million dollars a year.