This happens every few bowls - one random noodle that you did not order will somehow end up in your pasta. I don't know what kind of chaotic bacchanal the kitchen at Olive Garden is, but if they can't keep their noodles straight, what does that say about the rest of their health and safety protocols?!
Nothing, probably. It's just a freakin' noodle, man.
Pictured here is Crouching Penne, Hidden Spaghetti - can you spot it?