something similar happened with my kitten. I had just gone grocery shopping and there was a plastic bag on the table she was playing with while I was putting groceries away. She was having a grand time jumping in and out etc. When she got bored, and jumped down, the had gotten her neck in through one of the handles. Of course, the bag followed her to the ground flapping and crackling, and she just took off running scared as can be.
She ran so fast in big circles around the 1st floor, she would take corners so fast she would just slide into the opposite walls really hard. ;( it was pretty scary, especially since I was trying to catch her, and all I saw was this grey streak with a white thing flapping behind it. After about 2 revolutions, it eventually slid off her, and she darted up next to the window she sits by.
I have never seen my kitten shake so badly before, she was absolutely traumatized, terrified, curled up into the smallest ball ever and just shaking. I tried picking her up to comfort her but she wanted none of it, just to sit and shake. So I let her be, and she calmed down a bit.
This happened a couple of weeks ago, and whenever she hears the plastic bag noise, no matter how softly, she just bolts to a safe spot.
I guess instincts, and things attached to kittens make for some bad situations. I'll have to watch out for her and 'da bird' to make sure she doesn't get tangled and run with that.