We covered an earlier NICA decision on this case in 2016, when the case was remitted back to an employment tribunal due to concerns about the adequacy of the tribunal's investigations:
https://www.legal-island.com/articles/uk/case-law/2016/mar/caroline-connolly-v-western-health--social-care-trust-2016/

After another tribunal decision, it has now been heard again and a majority of the Court of Appeal has found in favour of the employee.

The appellant, a nurse at Altnagelvin Hospital, was dismissed for gross misconduct. She suffered from asthma and during the course of her shift felt the onset of an attack. She used a Ventolin inhaler from a locked medicine cupboard to combat the effects. On a previous occasion the Ward Sister had provided her with non-prescription cough linctus. She promptly informed the Sister of what she had done and promised to replace the inhaler with her own prescription. She was notified of her suspension pending further investigation and was subsequently dismissed following a disciplinary hearing.

She appealed the decision to an Appeal Panel but was unsuccessful. The Industrial Tribunal ruled her actions amounted to gross misconduct and that she had not been unfairly dismissed. The Tribunal had to determine whether the employer’s conduct fell within the band of reasonable responses.

Article 130(1) of the Employment Rights (Northern Ireland) Order 1996 provides that, in determining whether the dismissal of an employee is fair or unfair, it is for the employer to show the reason for the dismissal. Where the employer has done this, the determination of whether the dismissal is fair or unfair will depend on whether the employer acted reasonably or unreasonably in treating it as a sufficient reason for dismissal and shall be determined “in accordance with equity and the substantial merits of the case”.

Lord Justice Deeny in this Court of Appeal hearing said the Tribunal had to consider the proportionality of the sanction imposed and was unconvinced as to whether this was adequately achieved given the Tribunal acknowledged that the penalty imposed was “at the extreme end”. He concluded the appeal process carried out by the Respondent Trust was “fatally flawed.” The Court of Appeal held the Tribunal erred in law and quashed the decision that the appellant was fairly dismissed.

Lord Justice Deeny said the appellant’s actions “could not constitute deliberate and wilful misconduct” justifying summary dismissal. The appellant’s Terms of Employment did not expressly prohibit such a use and the Code of Conduct was ambiguous on the topic. He emphasised that dismissals for a single first offence require the offence to be of particular seriousness:

"Clearly there is a distinction between prescription and non-prescription drugs but it appears wholly disproportionate for one action to be lawful and permissible and the other action to be visited with summary dismissal, particularly in the case of a relatively inexperienced nurse with no previous disciplinary findings against her. I conclude that the Tribunal’s findings in these three respects were based on “no or no sufficient evidence” and were “plainly wrong”."

Lord Justice Gillen, dissenting, felt there was no basis upon which the Court of Appeal could consider the Tribunal’s conclusion was plainly wrong. He said that taking a prescription drug from a locked ward for the appellant’s own use was “clearly an extremely serious matter which no hospital could or should tolerate”.

Read a full summary of the case on the Law Society website:
https://www.lawsoc-ni.org/court-of-appeal-quashes-decision-of-industrial-tribunal