Gaiden said:I hope that was sarcasm at work.
No, it was Hyp being accurate with the rules.
There is absolutely no rule about dropping items when asleep.
However, I view certain game element omissions to be "no brainers" when adjudicating.
DMG page 9: "Look to any similar that is covered in a rulebook. Try to extrapolate from what you see presented there and apply it to the current circumstance."
So, if a PC (or NPC) falls asleep and a player asks if the character dropped his weapon, I will state "This is no different than Stunned in this regard. The character is not conscious, so he cannot consciously hold onto a weapon."
It is just common sense that if Asleep, Dead, or Unconscious, a person would "drop any weapon". This makes even more sense than dropping a weapon when stunned every time (without some form of will or possibly reflex saving throw).
From a totally "literal rules perspective", however, Hyp is totally correct.