This manual vote request only happens if the node is shut down while a fork is being negotiated and doesn't see the final conclusion. Because it's a lattice, it's only affecting the one account that intentionally created the fork, the rest of the chains are unaffected.
And if that one account had sent a lot of transactions which, say a large proportion of recipient accounts then built upon, it surely affects more than just that one account in total?
Partition tolerance, yes, partition detection is different though. With voting if I'm getting votes that sum to 15% of total supply, the network is split. With hashing if I'm getting a 1Mh/s rate is the network split? Maybe. I can guess if I know and trust an expected hash rate.
That only makes sense if you know what percentage of total stake is supposed to be voting at any one time.