Some dairy farmers by me have about 100 - 300 dairy cows, I always thought they were pretty good size operations with each farm having a lot of big tractors and tons of equipment, many big barns, buildings, silos, 1000s of acres of land to grow their own crops for feed and so on. Each one probably has 10 - 20 people who work there, maybe more in the summer.
But 18,000 cows? Seems like that operation would be the size of a not too small city with hundreds of workers working 24/7, yet nobody got killed? But 18,000 cows got killed? No way, not possible to happen by accident.