I would agree with this rule, you shouldn't be able to go above the max score possible. For example this is from a very popular tournament and the leader with handicap score is above max score.
MEN’S SINGLES:
1 ED SOBLESKIE - MILTON, FL – 916 (PENDING)
2 KEVIN RORKE - BELLE VERNON, PA – 892 (PENDING)
3 RONALD SUAZON - COURTICE, ONT - 866
4 CHAD NOLAN - NORWOOD, ONT - 857
5 JASON BEAUDOIN - OMEMEE, ONT - 854
6 RONALD B MANN JR - ASHEVILLE, NC - 852