Why wood cups and crowns
Wood absorbs moisture unevenly. When the underside takes on water faster than the finished surface, boards cup; as they dry unevenly they may crown instead.
Drying in place
Specialised drying methods can draw moisture from beneath a floor assembly. Whether this succeeds depends on the species, the finish, the subfloor and how long the water was present.
Give it time before deciding
Wood often improves as it equilibrates. Decisions about sanding or replacement are best made after drying is complete and readings have stabilised, rather than while the floor is still moving.
This guide is general information. Conditions vary between properties, so decisions about your building should follow an assessment of the affected areas.