Free Throw lane spaces

[jTheUmp]

Had this situation today in a rec league game (NFHS rules):

Team A, up by 5 points with about 8 seconds left in the game, with A1 shooting a 1-and-1 free throw. Team B is granted a timeout prior to the first free throw.

Coming out of the timeout, A1 positions herself at the free throw line. The rest of Team A players remain in their backcourt. All of Team B's players remain in team A's backcourt.

According to rule 8.1.4c, the first two lane spaces "shall" be occupied by Team B. I informed Team B that they needed to have players in those spaces, which caused Team B's coach complain that "they didn't have to have players there". After a few seconds, Team B relented and put two of their players in the first two lane spaces.

My question: what is the penalty if Team B refuses to occupy the first two lane spaces? I can't find anything in the rule book or the casebook to address this situation.