When the simulation code sees a cycle pass through a
wall that reports it was built at a later time than the
crossing time (because, for example, the player laying
it down has lower ping), then currently (0.2.8.2), for
lack of time to test a better solution, the owner of
the future wall is killed outright without a chance to
be rescued by rubber.
Preliminary tests with more sensible and less drastic
solutions made the two colliding cycles pass through
each other, but a refined variant of that code should
be ready and tested for 0.2.8.3.