Ms Brenda Plunkutt was an operator of a CAT 793F haul truck (weight:  150,000 kg’s unloaded, 300,000 kg’s loaded), employed by Thiess Pty Ltd at the Mt Owen mine.

A “category 3” alarm sounded which required the operator to immediately shutdown the truck to prevent further damage.

Ms Plunkett’s response was to find a safe spot to park.

This matter was very much about mine safety.


·         Took 1 minute and 36 seconds

·         Traveling 700 metres

·         Engine ceased = $500,000 damage bill

The truck was fitted with VIMS (management system/black-box) and GPS – hence the specifics of the evidence.

Mine Manager stated:

“The stage 3 alarm can indicate serious damage to equipment and if you are driving a truck at 50 kilometres an hour and the engine “pops out of the housing and blows the truck to a million pieces…(that) is a bigger hazard than stopping the truck on a ramp.”

Incident was caused by a maintenance error (“engine oil pipe joint bolts had fallen out and pipe joint has come apart allowing all oil to leak out”), but this was not accounted for in the decision.

Case law considered

  • Employees must obey all lawful commands that fall within the scope within the employment relationship and that are reasonable: [141R v Darling Island Stevedoring and Lighterage Co Ltd; Ex parte Halliday and Sullivan] and [Woolworths v Brown]
  • McLean v Tedman, Mason, Wilson, Brennan and Dawson JJ stated:

“The employer’s obligation is not merely to provide a safe system of work; it is an obligation to establish, maintain and enforce such a system…

…in deciding whether an employer has discharged his common law obligation to his employees the Court must take account of the power of the employer to prescribe, warn, command and enforce obedience to his commands.”

  • Parmalat Food Products Pty Ltd v Kasian Wililo, a decision which considered a dismissal related to a safety breach, the Full Bench stated:

“In our view this case raises important questions about the respective rights and obligations of employers and employees in relation to safety requirements at the workplace. Employers have important statutory obligations to maintain a safe place of work…Establishing and enforcing safety rules are an important obligation, a breach of which can lead to serious consequences.

In this case the employer considered and established to the satisfaction of the Commissioner, that Mr Wililo had breached its safety rules and his conduct amounted to serious misconduct. Clearly disciplinary action was necessary and appropriate because a failure to do so can send a message to the workforce that safety breaches can occur with impunity.

  • Hungerford J in Pastrycooks Employees, Biscuit Makers Employee & Flour and Sugar Goods Workers Union (NSW) v Gartrell White (No 3), (Gartrell White):

In cases of summary dismissal, the onus falls to the employer respondent to prove the conduct as alleged occurred:

“The right of an employer to summarily dismiss an employee without notice is qualified by the employee inter alia having committed an act of misconduct; thus, to be able to rely upon the right, and to pay the employee up to the time of dismissal only rather than terminate by notice or payment in lieu of notice, the employer must not only allege misconduct but must also prove it.

“…the act of misconduct or of disobedience had to strike at the fundamental aspect of the relationship of employer-employee so as to make it plain that the conduct complained of was such that the non-offending party may properly conclude that the offending party no longer intended to be bound by the provisions of the employment contract. In other words, so it seems to me, the test comes down to the question whether the employee’s conduct has been so inconsistent with his duties under the employment contract that it strikes down any reasonable suggestion that the employer-employee relationship can be continued in the future.”

  • Laws v London Chronicle (Indicator) Newspapers (Ltd), 160Lord Evershed MR (Jenkins and Willmer LJJ agreeing) stated:

“The question must be – if summary dismissal is claimed to be justifiable – whether the conduct complained of is such as to show the servant to have disregarded the essential conditions of the contract of service.”

The decision

Commissioner Stanton determined:

  • The allegations put to the applicant during the disciplinary meetings conducted as part of the respondent’s investigation were serious
  • The applicant had received training in how to respond to stage 3 alarms on more than one occasion. In any event, when the applicant finally did hear the sounding stage 3 alarm, she proceeded to shut the vehicle down in a fundamentally stable area at the bottom of the ramp. By that stage, the vehicle’s engine had lost its oil and the engine had seized
  • The applicant’s response was inconsistent with the respondent’s Transport Rules in operation at Mt Owen and the training that she had received
  • In my view, the applicant’s conduct can be correctly characterised as serious misconduct…[her] behaviour…had the capacity to cause serious or imminent risk to a person’s health and safety in accordance with Regulation 2(b) of the Fair Work Regulations 2009 and seriously breached the respondent’s transport rules, safety procedures and policy
  • The respondent takes its safety obligations seriously and is entitled to expect its employees reciprocate
  • Despite a number of opportunities afforded to her, the applicant failed to acknowledge that her actions were in breach of the respondent’s Transport Rules, safety procedures and policy for which she had received training. Safety rules and procedures are mandatory policies
  • The applicant’s dismissal was for reasons identified in evidence and explained in the applicant’s letter of dismissal
  • The applicant was presented with her show cause letter and…the applicant was formally instructed that the respondent was relying on those reasons to support her possible dismissal
  • The applicant’s explanation was that she thought she was “doing the right thing” in response to the situation that was at hand
  • The respondent is obliged to take reasonable care to provide all employees with a safe place of work and safe systems of work at all times
  • The applicant’s conduct, when viewed in its totality, amounted to gross negligence as alleged by the respondent. Her conduct…represented a very significant departure from the response expected of an experienced operator particularly given her training and the express instruction given to operators at the tool box meeting that she attended…
  • Her conduct also goes to the relationship of trust between the respondent and herself. It was also conduct that was in breach the implied term in her contract of employment to comply with the lawful and reasonable directions of the employer
  • The respondent had a valid reason to dismiss the applicant and was entitled to terminate her employment summarily


By way of commentary, whilst the applicant’s actions could be described as a “mistake” (albeit expensive) or “poor judgement”, Thiess was able to very competently focus the Commissioner’s attention on:

  • Evidence of the incident and health and safety “theme”
  • The steps it took to not only investigate, but the process in which the applicant was kept informed (and was under no illusion that this was a serious matter), including the “show cause” letter

It also provides direction on not only “managerial prerogative” and the thinking that should go into “summary dismissal” decision making.

[1] Brenda Plunkett v Thiess Pty Ltd (U2013/14637)

Greg Reiffel Industrial Relations & Human Resources Consulting has been providing the following services to businesses for over 30 years:


  • General HR and IR advisory service.
  • Fair Work Commission representation (eg unfair dismissals, adverse actions, etc.).
  • Workplace investigations and mediations.
  • Policies and procedures.
  • Discipline & Termination.
  • People Audits (are you at risk of prosecution?).
  • Enterprise Agreements, Contracts of Employment, Individual Flexibility Agreements.
  • On-site HR services.

Contact Greg on 0438 906 050 or mailto: