If a massage therapist invokes a therapist's "right of refusal" to give massage in a case where massage is contraindicated, which specific principle of massage therapy is upheld?

The principles of beneficence and non-maleficence are obligations of the massage therapist to maximize the possible benefits of massage (beneficence) and to avoid or minimize possible harms to the client (non-maleficence). Both principles are based on what's in the client's best interest. Non-maleficence requires a massage therapist to refrain from something that goes against the client's interest.