Off the top of my head, maybe worth checking this:

The first server to realise it cannot talk to the other nodes will make a 'dash' for the quorum file and lock out the other servers from accessing the file. The other servers once they realise they cannot talk to the other will also make that dask to grab the quorom file. Once they realise its locked, they will shutdown abort to preserve data integrity. In your scenario, one node will remain up.

The other nodes have to shutdown if you think about it, otherwise data integrity, consistency is compromised.

Bazza