The Doctor reports Kes's body temperature ranging from 14°C to 16.9°C. This converts to 57.2°F to 62.4°F. This is well below ambient room temperature and would make Kes even colder than a cold-blooded creature.
The Doctor says there are no other Ocampans on board to compare with, although there are two others, Kes's daughter Linnis and her grandson Andrew; however, the Doctor was referring to the symptoms of the morilogium - which only affects Ocampa in the final stage of their lives - he had no other Ocampa to compare them with. Since Linnis and Andrew haven't reached that stage yet, the Doctor's statement is quite correct. Furthermore, Linnis and Andrew are both only part Ocampan, so their genetic structure is likely to be different anyway.
Neelix's fudge cake for Kes's ninth birthday has ten candles. It is traditional for some cultures to add one candle for "Good Luck."
When Kes experiences the Year of Hell, then-Captain Chakotay tells Kes that there's only life support on three out of fourteen decks. Voyager has fifteen decks; however, though [link=Year of Hell (1997)] establishes that Deck 5 is virtually destroyed during a Krenim attack which left only fourteen decks usable, so Chakotay's statement was accurate.
Chakotay wears the provisional "Maquis" rank bar during Kes' ninth birthday despite being shown with captain's pips both before and after that point in the alternate timeline.
While crawling through the Jefferies tubes to reach the torpedo lodged on deck 11, Kes somehow knows how to locate and use the emergency equipment to manually override the hatch closures. It's been established that she only remembers events that have occurred to her since she was placed in the bio-temporal chamber and began moving backwards through time. As she never used the Jefferies tube in her future-history, she should not have this knowledge.
When Doctor "Mozart" is attempting to prevent Kes from jumping back further in time, she slowly, physically fades out of view. But only her mind has been shown jumping through time, not her physical body.
Early on (when Kes is old), the Doctor and others have no memory that Kes figured out in the past (later in the episode) that she was jumping backwards in time. In particular he is surprised she knows about the bio-temporal chamber he "just thought up," although it forms part of the discussion which happened six months prior.
37:04 Janeway says "in all my years I have never come across a phenomenon quite like this." Even if she hadn't personally experienced it, she should at least be aware of it, as the same thing happened in All Good Things... (1994).
Doctor van Gogh tells Andrew to hurry. Andrew walks, not runs, towards the sick bay door. Chatokay enters and grabs Andrew by his arm for hurrying. (Was it really for the kid's speed (which he lacked) or was Chakotay stopping him for not acknowledging his (Chakotay's) presence?) Released, Andrew continues with his unhurried steady pace.
In the future where the Doctor has selected the name "Van Gogh," the crew use the common American pronunciation, "van go." The correct Dutch pronunciation is closer to "vahn hohh," with a more open "a" in "van" and a soft "g," resembling an "h," at the beginning and end of "Gogh."
After Kes has jumped six months back from her birthday, the Doctor briefs Captain Chakotay on the situation, saying that in six months he will expose Kes to the bio-temporal chamber in an attempt to stop her aging. The bio-temporal chamber was previously said to reverse her aging, not just stop it.
Neelix refers to calories. Starfleet uses the metric system so the Universal Translators should have converted whatever Neelix said in Talaxian to Kilojoules.
After assuming command of Voyager, Captain Chakotay is seen wearing standard Starfleet rank pips on his uniform collar. Setting aside the issue of whether a provisional officer would be allowed to assume full command of a Starfleet vessel, he would not be entitled to wear full rank pips.