I remember reading (some time ago, and I can't find the article now) that YouTube view counters are designed to be probabilistic and "good enough" to give a general idea of the number of views. I don't believe YouTube is providing any particular guarantee on the accuracy of their view counters.

Lock-step global counters, even when you play games like sharding and summing to reduce contention, can still introduce latency and SPOF. But then again, I would have expected any probabilistic counter to only kick in after a certain popularity threshold.

I would hesitate to make any claim that something definitely was not viewed based on anything less than the full HTTP access logs of a self-hosted video.