Faulty server (can't modify data - just forks).
updating:
c1: -<c1_u1>----------------------------------<c1_u2>-----------------------------------
c2: --------------------<c2_u1>---------------------------------------<c2_u2>-----------
ordering:
/--------(c1_u2)------------------------- version for c1
s: -(c1_u1)-------------(c2_u1)-----<
\--------------------------------(c2_u2)- version for c2
c1:-(c1_u1)-------------(c2_u1)---------------(c1_u2)-----------------------------------
c2:-(c1_u1)-------------(c2_u1)---------------------------------------(c2_u2)-----------
Server may show different version to different clients.
Clients can be sure that they will be partitioned forever after fork (server misbehaviour detection).
Conflicts resultion: detection is enaugh.
Untrasted server (fork is the only way to lie).