Apparent misconduct or a medical concern: are employers conducting appropriate investigations?

Ms Dallimore was employed as a Customer Liaison Manager until her dismissal in May 2024. She had bipolar disorder, which her employer knew about before the disciplinary process began.

After returning from lunch, she appeared unwell, displaying drowsiness, slurred speech and confusion, and falling asleep at her desk. She denied alcohol or drug use and said the symptoms may have been linked to prescribed medication taken at an unusual time.

The employer suspended her, relied heavily on anonymous witness evidence and dismissed her for gross misconduct.

However, the Tribunal found that the dismissal was unfair because the employer did not properly investigate the medical explanation or gather basic evidence before concluding that misconduct had occurred. It found that the incident was likely connected to Ms Dallimore’s bipolar disorder and/or medication.

Suspension, disciplinary action and dismissal were therefore unfavourable treatment arising from disability. The employer had also failed to make reasonable adjustments, including treating the incident as a welfare issue, obtaining medical input and ensuring a fair process. Its use of additional disparaging witness statements amounted to harassment related to disability.

The case highlights three important points for employers.

Do not assume misconduct where there may be a medical explanation

This case did not involve a safety critical role, but the points still apply to such roles. Where an employee appears unwell or under the influence of drugs and alcohol, managers should not automatically assume conduct in breach of a policy but should investigate medical causes before moving straight to discipline. This is especially the case if a disability is known or suspected.

Fair process matters even where safety concerns are real

Employers should gather evidence, test assumptions, avoid overreliance on anonymous statements and give the employee a proper chance to respond.

Medical episodes should be treated as welfare issues first

Where behaviour may be disability-related, reasonable adjustments and welfare steps should be considered before disciplinary action is taken.

Safety concerns may require an employer to act quickly, particularly in safety-critical roles. However, acting quickly does not remove the need to investigate fairly.