This has been on my mind since last session, so I thought I'd put it up to the tribunal if I was in the wrong for this call.
To sum it up, the party cleared out a dungeon a couple of sessions ago, and returned to town last week to sell their loot and buy supplies. During the buying spree, one of my players brought up that the total gold amount they'd get from selling the treasure doesn't make sense, and that it seemed like the loot from one of the rooms they cleared isn't present in the group inventory.
This was followed up by each player essentially going "Well I don't have it, I thought Player B said they were taking it" and then Player B saying "No I never said that, Player C told me they were handling the loot sheet", and so on. Based on pure vibes, one of the players said that they vaguely recalled the treasure in that section being worth about 100gp, and asked me if they could just add that onto their sheet.
I didn't feel like going back through my notes and the module book to double-check to make sure that amount was correct, and I felt like it was such a small amount for them atm (they're pretty wealthy, 100gp isn't a huge loss), so I made a judgement call in the moment to basically be like "No, you misplaced it. Maybe that moneybag fell out of someone's backpack, but you can't just get it back for free."
There was some mild grumbling around the table, but the session continued as normal. At the time, I thought it would be a good reminder/teaching moment to keep good notes, but it's stuck in my mind for the last couple of days. Would you have given the gold back to the party?