Leveraging accurate clocks doesn't let Google ignore partitions. "TrueTime itself could be hindered by a partition"[0]. Spanner also uses two-phase commits and locking, which are unavailable under certain kinds of network partitions.
From their 2017 paper on Spanner and CAP:
> To the extent there is anything special, it is really Google’s wide-area network, plus many years of operational improvements, that greatly limit partitions in practice, and thus enable high availability.
From their 2017 paper on Spanner and CAP:
> To the extent there is anything special, it is really Google’s wide-area network, plus many years of operational improvements, that greatly limit partitions in practice, and thus enable high availability.
[0] https://static.googleusercontent.com/media/research.google.c...