The customer didn't do anything wrong.  There was an out of place truck sitting for a couple days, it was called in like any place would do.  

The problem was trusting that one person would tell everyone in the store to not worry about it.  He probably didn't communicate like he should.  A follow up to the general manager should have been made in the morning, miscommunication is the root of most problems, including this one.

Brush it off and move on, don't lose a customer over it.