Trust and distrust are not straightforward contraries.
I have read that the human brain processes experiences of distrust in the amygdala, which NIMH [somewhat informally] describes as "[t]he brain's 'fear hub,' which activates our natural 'fight-or-flight' response to confront or escape from a dangerous situation." Experiences of trust, on the other hand, are processed in the prefrontal cortex, the "[s]eat of the brain's executive functions, such as judgment, decision making, and problem solving."
Amygdala Oakshott, impervious butler of Cortex Hall.
When we disagree with someone we trust, as long as we don't perceive that disagreement as somehow dangerous to ourselves, we can still reason our way through that disagreement using our prefrontal cortex. But if we distrust someone outright, then our amygdala is likely to intercept whatever they say as a threat that demands an immediate response, in effect short circuiting our reason.
Hence the value of building trust with (and the absolute necessity of dispelling distrust from) someone with whom you have something to communicate.