There are certain things you just can't predict, and have to learn in the field...
One particular cow ("Evjelin" IIRC) would try to avoid her own calves because (it seemed) she much preferred the machine it seemed.
The final year we found her calf with a broken neck in a flat area of the pasture. (Yes, they were always allowed to stay outdoors around when they calved and usually they spent a few days outside together. Mostly this was great I think and except this incident I only remember one other were it was a problem: one calf had got under the fence and into the bog and the cow had followed it into the bog and it was a real mess and I was a really proud teenager when I was able to get out the calf. Both of them needed help to get out but both survived and recovered nicely IIRC.)
(source: grew up on a tiny dairy farm)