On its face, this sounds like simple ashes thrown in others’, in this case, law enforcement officers’ faces.
That is disturbing enough.
Next thing you know, LEOs will be “trained” to allow foreign matter to be thrown/expelled in their faces...just in case it’s angry family throwing ashes.
Throwing anything at all at another person, ashes or anything else, could and should be charged as battery.
If the settlement resolution is any indication, they will probably require Beck to say "thank you and may I have another?"