The tape recorder in the lab has the reels rotating in opposite directions. This indicates that no tape is in the machine. Normal operation has the reels moving in the same direction with the speed varying depending on the quantity of tape on each reel.
Yves, talking about chimpanzees, says "...as it's the closest relative to man, genetically speaking". From the genetic point of view, the closest animal to human is bonobo (pan paniscus), a kind of ape.
The address of the National Zoo is 3001 Connecticut Avenue, NW, Washington, DC, not 3000 as indicated on a shipping label. 3000 Connecticut Avenue is across the street from the zoo. There are a large number of mental health professionals in the building.
When the Lone Gunmen, Eve, and the chimp are hiding in the barn, Amabilis fir trees surround the building and farm. They are supposed to be in Massachusetts but Amabilis fir trees do not grown in the eastern United States (filmed near Vancouver, BC).