But again, you are making a general statement with specific assumptions.
In a Beer and Pretzel, Hack and Slash game is there necessarily any behind the scenes information? Is there necessarily a single story to tell?
And why can't the table come to a consensus about what the DC might be? We have a scale, Easy: 10, Medium: 15, Hard: 20, Nearly Impossible: 25 and a lot of items and things pre-listed out.
And if anything happens that doesn't make sense... well, they know exactly why it happened. No one at that table is going to be overly upset that they did a listen check, failed because everyone agreed it would be hard to listen through a thick wooden door, and opened it to find the random dice table says Ogres in platemail. The player can say "I totally would have heard that" and everyone else... is likely to agree, but they all know that they made a decision, and that decision was upheld.
I mean, when the group makes a decision, who do you get angry at when the decision turns out differently than you expect? It wasn't the DM hiding information from you for a cheap surprise, you guys made your calls, and the dice made a silly situation, something you knew was possible when you started a game this way.