20880302_ferences__July_2014_FIDE_Laws___FIDE_rule
[0] 9. [USCF rule] To claim a win on time in a non-sudden death time control, the opponent must have a reasonably complete scoresheet with no more than three missing or incorrect move pairs for the time control. A player may call his own flag as a means of preventing the opponent from filling in missing moves on the scoresheet. (Once the flag has been called, the opponent may not update the scoresheet.) [FIDE rule] 
It is not necessary to have a complete scoresheet to win on time in a non-sudden death time control. Calling your own flag to prevent the opponent from filling in moves on an incomplete score sheet won't help.
The United States Chess Federation - USCF - FIDE Rule Differences (July 2014 FIDE Laws)
FIDE rule