Dr. Bashir states that it is illegal to enter into a holosuite while it is in use. This is often believed to be contradicted by the many instances of this happening throughout Star Trek: Voyager (1995) and Star Trek: The Next Generation (1987); however, those shows take place on Federation starships, and would therefore be subject to Starfleet regulations. This incident takes place aboard a Bajoran space station, however, and would therefore be subject to Bajoran law, not Starfleet regulations. Therefore, it may well be illegal on DS9 for someone to enter into a holosuite in use, while the same behavior is overlooked, or even allowed, onboard Starfleet vessels.
LED (light emitting diode) elapsed time displays are shown on various control panels in Doctor Noah's fortress in 1964. Although LEDs weren't invented until 1970, this is the classic "supervillain" plot device of James Bond movies, where the antagonists often had surprisingly easy access to improbably futuristic technology.
Eddington is missing one of the rank pips on his collar. He's a Lieutenant Commander but he's wearing the rank of a junior grade Lieutenant, a much lower rank.
When Dr. Noah first begins talking to the group in his home on Everest, the background sky reveals seams and stitching along the top-left area, obviously a backdrop.
The Russian character is named Anastasia Komananov. For a female, the letter A should be added to the end of her last name: Komananova.