This is another UK case that could be of persuasive importance in Irish courts and tribunals. The respondent in this GB Employment Appeal Tribunal case is responsible for inland waterways within Scotland. The British Waterways Board operates in Scotland under the name “Scottish Canals”. It employs about 160 manual workers who work a seven day rota. They are also on standby for seven days one week in every five. During their standby period they are not permitted to consume alcohol.

The claimant was not happy at work and it's fair to say he wasn't the only one. There had been a number of complaints about health and safety and other matters and a recommendation to go to mediation was on the table when the employee was suspended for comments he had made on Facebook. As well as derogatory terms about his superiors, he made several references to drinking on duty or turning up half drunk. 

The claimant said the entries were banter between colleagues and his settings on Facebook must have been switched from private to public. He did not mean to offend anyone. He referred to 'bw', which was taken to mean British Waterways, however. He was dismissed but won at the original employment tribunal, the tribunal stating that the employer did not take into account a number of mitigating factors, such as the employee's apology and "The nature of Facebook and the fact it is a social media site used for chat, and frequently involves people making claims which are either exaggerated or simply not in fact true."

The EAT has reversed that decision. It found that the employment tribunal had substituted its own opinion for that of the employer, whom the original ET had found had followed a fair procedure. The employer had in fact considered the mitigating factors - they just didn't, in the opinion of the employer, outweigh the offence. The ET should have given more weight to "the employer's views about what did happen, and asked itself if the respondent’s reaction in light of those views was within the reasonable range of responses."

In a rather sad and salutary postscript to the dangers of using social media inappropriately in relation to your employer, the EAT noted that the claimant has not been able to find employment and is at the first stages of bankruptcy procedure. 
http://www.bailii.org/uk/cases/UKEAT/2015/0004_15_0308.html