Actually, I never understood the big deal about the plates. Why couldn't it have just been the victim's family telling him the plate number, and him calling it in to verify?
The most frustrating bit to me was the EDTA business, and how the lack of proof that it came out of the vial somehow made irrelevant the tampered evidence package that the syringe-sized hole in the tube.
The package being tampered with was problematic, but the hole is made when the container is filled with blood not when removing the blood. If you're removing blood, you just take the lid off.
During the inspection of said package by the defense attorneys, they mention having asked the staff whether a hole in the lid should be expected, to which they replied "we don't do that". This was the "Okay, this documentary is over now. Next scene will show the judge dismissing the case based on newly discovered evidence, right? RIGHT?"-moment for me. Not so much.
To be fair, that wasn't the only scene where I felt that way ...
They never specify what he asked them, so it's hard to know.. He might have asked if they use a syringe to access the blood in the vial, which they wouldn't since you can just remove the rubber stopper and have complete (undetectable) access.
Hard to find good pictures, but you can see here: http://i.imgur.com/mhdkpui.jpg some vacutainers (newer, but they work the same) that have been filled, complete with puncture holes. That's just how you fill them.
It's a lot more compelling that the evidence box has been tampered with, in my opinion. You can find a few phlebotomists confirming this in the makingamurderer subreddit, if you look around.
The most frustrating bit to me was the EDTA business, and how the lack of proof that it came out of the vial somehow made irrelevant the tampered evidence package that the syringe-sized hole in the tube.