Re examining early evidence, statements, transcripts, knowing what we do now

I know we have discussed this at other times when we had been at other sites.

http://www.wftv.com/_blank/18740699/detail.html

On page 7 of 18, there is a light bulb that goes off to the detectives who go to the evidence unit and open the box of items Cindy offered to LE on July 16th. They immediately notice the garbage bag CA put the items in to give LE, is the same as the bag Caylee's remains were placed in (sorry I know it's graphic). The also mention the kitchen knife.
I know we have discussed this at other times when we had been at other sites. However, I am wondering if anyone here knows the statistics of finding these two bags match the same lot and run of bags? I'm also still thinking KC probably used that kitchen knife to tear the duct tape. I know there have been times, I am just not as strong to tear something or open a bag. I'm thinking if she was panicking to get the hail outta wherever she was, maybe she couldn't tear it. So, she used the kitchen knife. This to me would support the theory that she also had done this at home. Then brought the knife with her in the car. I do wonder what she did with the roll of duct tape if it was, in fact, in her car. Can they also match the roll of duct tape to the pieces found?
I just wanted to re examine some of the stuff we received early on based what we have learned since these early documents.