That timeline was formed based on the results of the PD's and DA's investigation into the matter. Are you objecting because it doesn't say that Gray was throwing himself around trying to get hurt? Or something else?
Because, if it's the "throwing himself around" possibility you're objecting to, then note the timing of the injury - after he was taken out of the van (still responsive) and then placed back in the van, in wrist and leg restraings, face-down on the bottom of the van.
For reference, here is a (stock) photo of the inside of a police transport van:
If he restrained at the wrists and ankles, face down, on the floor of the van, how could he have gotten himself up in order to throw himself around with enough force to break three vertebrae and crush his windpipe?
What is being cherry picked here? What other facts should be included?