2 things here.
1: Floating Explosive trap: If you throw a trap in solo mode and quit the game, the trap will float right in front of you and hover above the ground. The best part is, that the item will actually move up and down like a flying saucer. Good for a small laugh.
2: Trap Dud: When you spam explosive trap, there will be sometimes when you will see 2 traps fly out of your hand. One will explode, but the other will not. In fact, its a complete dud.