louise nesbitt was employed as an office bookkeeper at a perth company .
she mistakenly sent a text message to boss calling him ` a complete d *** '
it was sent on january 12 last year and she was fired for gross misconduct .
the long-time employee claims it was meant to be a ` light-hearted insult '
but the fair work commission ruled against her , saying text was ` hurtful '