The antonyms for the phrase "involved oneself" include distancing, disengaging, detaching, withdrawing, uninvolved, uncommitted, indifferent, and aloof. These words convey a sense of detachment or lack of interest in a situation, which contrasts with the active and invested nature of "involved oneself."
A person who distances themselves from a situation may not want to be closely associated with it, while someone who disengages lacks the motivation to participate. Detaching involves separating oneself from the situation entirely, while withdrawing suggests a deliberate removal from the situation.
On the other hand, uninvolved, uncommitted, indifferent, and aloof all show a lack of interest in the outcome or consequences of a situation.