Does an employee who performs the work of a negligent colleague contribute to that colleague's dismissal?

Employers and employees must adhere to the agreed-upon terms. If an employee violates them, he may be held accountable according to the contract, even if it leads to his dismissal, provided that the accountability does not lead to committing something unlawful. Your performing this employee's work while he is suspended or dismissed is not a reason for his dismissal, and you incur no sin by it, for a person is not held accountable unless he directly undertakes something or causes it.