"I don't know where her collar went..." Lol, you probably shoved it down her throat whilst shoving her into that bag.
Jesse, have you tried the pillowcase technique? I'm telling you, you get the fabric over the cat's head, and they usually stop freaking out so bad. Putting a cat feet first into a bag is tough to do on the ground...
Good job on the rescue! That was intense to watch!
SZ