Sadras
Legend
This to me would ruin all the mystery of a who-dunnit like this. No thanks. The shopkeeper should be a primary suspect. The reason to ask for an insight check is to maintain that air of mystery and doubt. The shopkeeper is less likely to be involved, but there's no way to be certain.
What air of mystery would that be?
1. The one where the PC knows he rolled well or badly or just plain average - leaving everyone else in the party make Insight check rolls too?
2. The one where the DM narrates that the shopkeeper shifts uncomfortably in his seat as questions are asked?
Firstly do you really need an Insight skill to notice that? Secondly, any suspicious descriptor now added by the DM about the shopkeeper means the PCs will press on with diplomacy, bribery and intimidation - and usually in that order.
 
				 
 
		 
 
		 
		 
 
		 
 
		 But I still think WotC (at least) should be trying to think about framing these challenges in a way that encourages creative thinking and not trip up DMs by documenting an assumed approach and DC and when the players try an obvious but different approach, leaving the DM to wonder why they bothered even writing that? I would much prefer they say something like "expertly disguised trap", or "hastily set trip wire", or something like that. Give us the flavor of the challenge, or the motivation(s) of the NPC (to pass onto the players) and let us worry about how to resolve the uncertainty. (And I guess it also assumes that there will be uncertainty, which again flies in the face of the PHB guidance, because a particular approach might eliminate all uncertainty, and their assumed approach cannot be the only one). There's a lot of useless fluff in the published adventures and not enough actionable information IMHO. I guess it makes for a more interesting read away from the table, but gets in the way when you actually try to run it.
 But I still think WotC (at least) should be trying to think about framing these challenges in a way that encourages creative thinking and not trip up DMs by documenting an assumed approach and DC and when the players try an obvious but different approach, leaving the DM to wonder why they bothered even writing that? I would much prefer they say something like "expertly disguised trap", or "hastily set trip wire", or something like that. Give us the flavor of the challenge, or the motivation(s) of the NPC (to pass onto the players) and let us worry about how to resolve the uncertainty. (And I guess it also assumes that there will be uncertainty, which again flies in the face of the PHB guidance, because a particular approach might eliminate all uncertainty, and their assumed approach cannot be the only one). There's a lot of useless fluff in the published adventures and not enough actionable information IMHO. I guess it makes for a more interesting read away from the table, but gets in the way when you actually try to run it. 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		