"Who says A, must say B." as Bill Buckley says. The problem with the "strong allegations" is they are completely unsupported by LEO behavior (can't prove Rick Robert's source is really LEO!).
By assuming usupported allegations (A), one is also saying (B) that LEO is either ignorant, incompetent, complicit, covering up......etc. etc. etc.
All of which may be true (or not), but where are the supporting rumors of (B), that LEO is involved in either gross stupidity or gross criminality.
LEO is either ignorant of allegations, investigated nothing. Not likely considering publicity.
LEO is complicit, criminal, and is covering up. Got any evidence/allegation/rumour/accusation of that?
LEO is aware of and has investigated this angle and discounted for reasons not shared with the public.
The first two are poorly supported by known facts. The van Dams may be evasive with the press, but they owe the media and the public, not one thing. LEO, to whom they owe a legal and moral duty of full cooperation, says they have gotten it.
I'm betting the cops are right. BTW, recent articles point out DW glaring lie about having left his wallet as a reason for the change in his "trip" plans.