I can't see how anyone who had just committed a murder would be stupid enough to dump evidence in plain sight, knowing their every move is being watched.
I completely agree that it is stupid. However, I think it fits with what a narcissist does. A narcissist thinks they are smarter than everyone else and that the rules don't apply, IMO. If PF is a narcissist, he could have thought that LE would not have looked, virtually in plain sight. JMO.