the problem is when you get the players that spend 10 or 20 minutes on everything because you foreshadowed. I get bored though when they get like that and sometimes weird stuff happens. like the door grows arms and puts the rogue in a headlock but does no damage. Or just have random patrols, or wizards or clerics scrying the area periodically. If they go too slow sucks to be them. If they want to spend that much game time on something so boring, I should get some fun occasionally.There is no "correct way to roleplay it". The player failed to find something, but the corridor is still as suspicious as before they started searching it. I did foreshadow the threat after all. I don't tell my players the corridor is safe, when it obviously is not. I tell them that they couldn't find a trap and that's it. How they act upon that knowledge is entirely up to them. They could proceed, or they could avoid the corridor. Both are valid choices.