A minor gaffe: It's inconceivable that Nikita would not know about Semtex after two years of training and one year in the field. A plastic explosive manufactured in the Czech Republic, Semtex is widely used by terrorist groups. It was an element in the mission described in "Mandatory Refusal".

The Impasse de L'Arsenal is a cul-de-sac off the rue des Arenes, near the intersection with the rue d'Auron, in Bourges, France.

The jamming device in Michael's office is operated via a keypad secured to a small, sliding panel beneath his desk. He activates it when he wants his conversations to be private. (A very faint, ululating sound is sometimes audible in the scenes in which he activates the device.) Whether he knows or just suspects that his office is monitored is never made clear. He often uses the jammer when he talks to Nikita.

It is unclear how there could be a tracker on Dian, unless Michael put one on him when they embraced, and Nikita would not have been privy to that.

DOD: The Department of Defense. Level Four: This is clearly an alert status, distinct from the Level Four more often referred to in the series, which refers to a level in the Section One facility, where Medical is located and where some operatives go to speak privately, as there are no eavesdropping devices in certain areas of that level.

It's not clear why Operations and Birkoff had to give such a performance in Comm, acting as though they were genuinely alarmed in the previous scenes, when this scene makes it obvious that they were in on a ruse that had to involve Michael's "jailbreak" with Rene. Probably it was deemed wiser to have nearly everyone else in Section believe there was an actual alert rather than to require the facility's entire population to join in the ruse.