Spartacan,
One can only presume that your lawyer neighbour qualified for the 50% reduction having met the required duration of service or that there was no qualification period in the practice. They probably had no need to stamp their foot and demand that the rules be changed to suit their circumstances.
When your partner has just flown 24 sectors in 5 days, you do get a slightly unsympathetic perspective on this
The plus side is that she's building plenty of hours so that if she needs a 50% roster, she'll qualify within the rules, won't have to claim sex discrimination and cost her employer a fortune in legal fees.