To me, the issue is not what should happen (or not happen) when one leaves luggage unattended, but rather what one can/should expect to happen when one leaves luggage unattended. That is because when you are in an airport on any given day, your personal beliefs about such things as civil rights, fear, appropriate responses and effective security measures will have absolutely no effect on security's likely, actual response to unattanded luggage.

I find it hard to believe that anyone with any recent airl travel experience could not have easily foreseen what ended up actually happening in this case. As such, I cannot understand why someone would leave their luggage unattended as was done in this case.