Formula 407 - S1-E12
Other mistake: At the start, the episode's textbox reads, "Fort Frazier Ordnance Testing Facility" with correct spelling, but in the next shot the base's sign reads, "Fort Frazier Ordinance Testing Facility" when it should actually be "Ordnance."
Answer: There is no logical reason. Any normal person would notice these type of absences. The show employs a "suspension of disbelief," which is a literary device where the movie audience or a book reader accepts that certain things are unreal for the sake of the story to be told. It is similar to no-one noticing that Clark Kent looks exactly like Superman because he wears glasses.
raywest ★