The president spoke truthfully; Sheridan could petition for a
promotion for her, but it's up to Earthforce to grant it, so the line
still tracks. (Note also there's no pronoun there; "Giving her a field
promotion." The imperial We still stands, though.) Also, Sheridan says
he put through the paperwork the day after he got there; which is fairly
close to the time frame in the story in which the President says they'll
be giving Ivanova a promotion. There's no discontinuity here.