I didn't listen to the entire thing (I've got things to do today) but I'll make a couple of observations,
1) some of the statements that sounded like non-sequiturs are most likely because the dispatch was still handling other calls and internal admin comms (for instance the pink slip comment).
2) The "Encrypted" comms are just that. The person recording this either doesn't have his motorola set on secure or doesn't have the right crypto loaded.
Finally 3) RE:"5:25 – PD has not requested your arrival at the scene yet – To EMS" EMS would not be let onto the scene until it's secure. It's highly unlikely that would be the case with a building the size of a school in any short amount of time.
Even a very good team will need to take time do methodically clear a route from the entry point to the casualties and set a perimeter. This means checking under, behind and inside anything that could conceal a person, in every room EMS would have to pass to access the casualties. Then posting some form of security on anything that has access to an uncleared space.
I didn't hear anything on those recordings that required tinfoil. It just sounded like a shitty situation that needed to be worked methodically.