When must a police misconduct hearing adjourn the proceedings for the attendance of the respondent officer or even a witness? The Police (Conduct) Regulations 2012 reg 33 [beware that the linked statutory instrument is now out of date, but not on this particular regulation] provides that a legally qualified chair (LQC) may adjourn the hearing in particular circumstances:
(3) Subject to paragraph (4), the person conducting or chairing the misconduct proceedings may from time to time adjourn the proceedings if it appears to him to be necessary or expedient to do so.
(4) The misconduct proceedings shall not, except in exceptional circumstances, be adjourned solely to allow the complainant or any witness or interested person to attend.
The meaning of exceptional circumstances presumably refers to circumstances that are an exception to the norm rather than those which are extraordinary. Regardless, the latest case from the Court of Appeal on adjournments in civil cases, Solanki v (1) Intercity Telecom Ltd (2) Guidinglight Finance Ltd [2018] EWCA Civ 101 is worth reading.