Accidentally threatened some dude at a band competition lmao

(Technically not a "competition" but for sake of simplicity, it is) Alright so picture scene. Im standing in front of a door with my friends, eavesdropping on another friend who was preforming because we didn't make it in on time. I feel someone hit my back and see it's my friend. Now, it's pretty common place that we jokingly threaten each other, nothing new, so I turn around and pretty loudly declared "get away from me, I'll kill you". Turns out she had backed away and some random guy (pretty sure he was a teacher too) was just chilling where I thought she'd be. I was genuinely so scared but I don't think he heard me because he just casually asks "what piece is he playing" afterwards. 

Embarrassing regardless, had to keep it in my memory