It seems the Passadena police learned quite a lot from this accident as their dispersal is much bigger and very differently marked - I assume they now have comms as well.
We trust that the painted markers are correct. We trust that the other machines will stay away from us. We trust that the landing instructions are correct. We trust that ATC is doing its job correctly. We trust that the other pilots are as smart as us. The entire scenario is built on trust. If we cannot trust, what do we do?
we never assume and always check as much as we can, never being afraid to ask questions whether it is of ATC or other pilots.
Blind trust is like expecting everyone else on the roads to drive perfectly all the time and we all know that doesn't happen.
If something is within your control - like checking the proximity of another aircraft, why not be sure rather than just 'trusting'.
The Flight Safety poster - ASSUME makes an ASS out of U and Me - seems appropriate.