Florida deputy Jesse Hernandez screamed “shots fired,” and frantically fired his gun after an acorn fell onto the roof of his squad car, making him jump.
In California it’s a bit longer, 3 -4 months. Still not really long enough, and aimed towards a certain type of person. It may not teach how to be a good cop, they will teach you to be in constant fear.
He has no known history of trauma. He was, IIRC, a special forces officer that was deployed (Afghanistan?), but he never saw combat operations.
This is more likely the result of being trained that everyone is out to kill cops, that cops are the "sheep dogs", and that they need to be ready to kill people at a moment's notice ("Killology").
Sometimes war veterans who have been in combat suffer from PTSD and react to loud gun like noises as if they are shots being fired. That is not the case here as it seems he did not take part in any combat while deployed but it certainly can be trauma.