Sporting Code 3, 2014, 3.4.a:
a. No declaration is required for a duration or gain of height badge flights that use only a PR or a stand-alone barograph for evidence (SC3-1.4.2), or for a straight distance flight so long as no pre-declared start or finish point is used (SC3-1.4.3).

If the header is incorrect, club records and OO proving which glider and pilot launched when should suffice...

Sporting Code 3, 2014, para 6.5:
Pilot and glider data Pilot and glider data stored in a PR or FR is not definitive until confirmed by the OO from independent evidence taken at take-off and landing. When any shared FR is used, pilot and glider data
may be from a previous flight, so care must be taken to see that the pilot and glider data is accurate; however, an error may be corrected by the OO for Silver and Gold badge claims.

Given this, have your OO correct the data, and submit... The sporting code is your friend.

2D