It really kills the mood for me as a DM, despite how obvious the solution was in that the guy literally had the solution sitting in his character's hands for like over a minute of combat. Dood is stuck in a room filled to the brim with enemies and he got cut off from his party by more of the enemies. So long as he does nothing they literally cannot find him due to shadow template and massive hide bonus cheese and he walked into the room with many fistfuls of grenades with the express intent to blow up everything in the room. He coulda done it from the hallway that led into the room, hiding just tossing them in around the corner thus being totally safe from the blast, but instead he spends several rounds hanging out at the corner and then when nothing happens he enters the room despite already knowing that it was FILLED TO THE BRIM with enemies. The combat was thus extended over 4 hours of play that could have been avoided but nooooooo grenades are tooooo expensive he doesn't want to use them all just like that even though they HAVE to kill these things. Completely disregarding the fact that I've been giving them much more than WBL so far and they are fairly low level so that means a lot.
Doesn't help that the guy has a really short fuse and I didn't want to make the whole thing even worse for everyone by saying something that would go by fine with the rest of the group but would have angered him immediately because he thinks I'm telling him what he is suppose to do and retorting with 'well I'm not good at coming up with clever solutions' WHAT IS CLEVER ABOUT A ROOM FULL OF WEAK ENEMIES AND YOU WIELDING A LARGE HANDFUL OF GRENADES THAT YOU EXPLICITLY SAID YOU WERE GOING TO USE TO KILL EVERYTHING IN THAT ROOM.