Mistakes are part and parcel of every analytic hour. Missed communication; timidity; a lack of sensitivity; getting caught in a complex; losing perspective; over-identifying; colluding with a pathology; these but a sampling of the various ways a psychoanalyst can miss the mark in a session.
So how to proceed?
From a Jungian perspective, whereby the third, the unconscious, is given more than mere lip service, any mistake provides the unconscious an opportunity to assert itself. For instance, Jung taught not to fear a misinterpretation of a dream because the next dream will throw light on where you were off.