Actually, warriors spell reflection isn't based on spell resistance whatsoever. The ability allows them to reflect any one spell regardless of resistances or of their level.

This means that if said mage were to cast a 10k frost bolt at the warrior, the warrior would be smart enough to cast his spell reflection at the point of the mages spell completion to reflect the spell.

Also, spell penetration only works on those who have moderately high resist gear. This means if a person has 30 resistance to a spell and you have 30 spell penetration, then your spells would land on the target as if they had 0 resistance. Spell Reflection is an reflection effect, not a type of resistance

10k frostbolt? get off the private server and then see how much a frostbolt does with that gear