It is important to distinguish between:

(a) a deliberate act of disobedience, as compared with

(b) a mere error in carrying out an employer's instructions.

It is also important to take into consideration whether the act of disobedience is trifling and isolated as compared with substantial and repeated. A trifling act of disobedience might be sufficient to establish just cause, if the employee had a history of such acts. In the end, the court will probably take into account the intention of the employee as the most important factor in determining whether the employee has been insubordinate.

Even if the employee commits a very deliberate act of insubordination, the employee may still be acting within his rights. The employer's order is required to be within the scope of employment. For example, an employer will not have just cause to terminate an employee because the employee has disobeyed an order to cheer for a particular professional sports team.

The employer's order must also be one that is lawful. If the employer's order amounts to a criminal or regulatory offence or a breach of the employee's professional obligations, then the employee will not be considered to be insubordinate in defying the employer's instructions.