You're the five year old daughter of Tony Stark and Pepper Pots. Happy Hogan is watching you, he looks away for one second and you run off. You're trying to play hide and seek so you run into a random room and it ends up being the room the Avengers are having the meeting in, Tony and Pepper had to step out, they said they would be gone for an hour. The second you burst into the room everyone draws their weapons thinking it's an attack.