Hey OP not sure if you are still active on this issue and not sure if this has been mentioned here but I will post, as i dont have time to go through and find it..
regarding the substitute teachers car and the bullet holes found in them.. some interesting connections have come up with this and the police tape where the officer says "theyre comming at me".. on that thread you will see a link to a photo of the carpark, in that photo you will see there are 4 cars taped off in the second row, and 1 car with police tape on it in the first row.. if you look behind the 4 cars that are taped off, there is an unmarked police car that, by the way its positioned, seemed to have come driving in and just pulled to a stop rather hastily, its not parked properly .. in the police tape when the officer says 'theyre coming at me' you can hear what sounds like a few gunshots, a pop pop pop.. now if you look at the picture of the car park, the position of the taped off cars, the sub teachers green car with the bullet holes, i believe the police officer above, pulled in, saw two suspects coming out of the school entrance, said 'i got em i got em, theyre coming at me.. and fired off a few rounds at them, they fired back.. this is possibly the reason for the 911 caller saying the shooting started up again.. then you hear the police request 2 ambulances.. these two adult wounded victims were reported days later.. but have never been identified... all this matches the physical evidence in the picture and matches up with the police radio..
Link to carpark photo (fyi, it loads automatically for me at 50% so you have zoom it up to full size):
[link to www.collegian.com
Police scanner recordings, real time, not edited:
[link to www.youtube.com
Substitute teachers car riddled with bullets article and video:
[link to www.cbc.ca