Wouldnt say it was all down to luck. Care and maintenance plays its role aswel. If you take the time to clean and lube moving parts, such as freewheels, they are certainly more likely to work for a lot longer.
In this time I have owned other freewheels such as Tensiles etc. I managed to break a Tensile after just 2 hours. Which could maybe be luck, or could be just a bad freewheel. But given a freewheel is manufactured to a high standard and is looked after. I see no reason why it should break.
Also, 72 engagement points is a fair amount compared to those shitty adicta(dicta?) freewheels that used to come on nearly every bike.