My father (https://bit.ly/3acZAAI), who is a certified CCSP Ethical Hacker and formerly worked @ZScaler/Checkpoint/Palo Alto Networks, would say that there are basically two scenarios: someone like him did it intentionally or someone like him did it by mistake.
Any other scenario of outsiders, code updates, etc - basically misses the point of how modern DNS infrastructure works.
Any other scenario of outsiders, code updates, etc - basically misses the point of how modern DNS infrastructure works.