That is a tragic story Matt.
You are absolutely right. Death is something we tend to ignore, but it happens to everyone. For some reason we tend to regard it as a taboo subject to talk about.
Nobody wants to upset a grieving person, hence people say something and then regret it, but only because they don't want to add to the pain.
My customer obviously wanted to talk, so my feeling of 'what did I say that for' went away pretty quickly.