The question is answered in the second verse, when the rising sun reveals that the flag is, indeed, still there:
What is that which the breeze, oer the towering steep,
As it fitfully blows, half conceals, half discloses?
Now it catches the gleam of the mornings first beam,
In full glory reflected now shines in the stream,
Tis the star-spangled banner...
Not trying to back up my post....I did NOT check into it...just thought it nice.
Although you have pointed out errors....And I'm glad you did.
FWIW-