What episode does Tuvok ask "what about the delta flyer?" And someone says "the what?"
TUVOK: The Delta Flyer. Its sensors are more advanced.
JANEWAY: The Delta what?
Tuvok is indeed having trouble with time-flashes
Tuvok has more intense hallucinations and collapses. At the same moment the Doctor and Janeway detect a burst of tachyon particles in Tuvok's vicinity, indicating temporal disturbances. His visions may actually be glimpses of the future.