You were right about the strength of twisting it made a big difference. Here is what I could gather (warning long post, TLDR whole story is fucky) https://voat.co/v/Conspiracy/comments/337863/1339736

Not very strong I will test with one of the bags when I get back to work and update you about my finding. Also I would want to see any photo of the incident. If there isn't a small knot tie from janitors to make sure the bag doesn't fall inside the trash container I'm immediately calling bullshit. It is one of the first things you learn is to pull a corner to stretch it and tie it off to save you from more work the next day. I have worked at several major janitorial companies and we all do that same thing (the newer janitors tear the bag itself then tie it off so that is something to look for too, there should be a small knot around 2 inches in length, more if the janitor is new and would be far more obvious) Most plastic bags might be able to be done that way, these cheap ones I'm not to sure about though. Like I said I'll give you an update on my findings in the next 24 hours. Edit: I found out what type of bag it is, it is the cheap 2.5-3 foot long clear plastic bags. If anyone could message me with a good estimate of how tall she was or her weight it would really help. Thank you.