when something actually happens it ceases to be a strawman. it might not be a representative sample (though the SRO running away and then going to court to fight for his right to run away after the parkland shooting does lend some credibility to the idea that we shouldn't expect help from the police, as does the police fighting in court to assert that they have no duty to protect people in the wake of that subway stabbing), but it is within the realm of possibility.
Except you gave a completely unrelated example and just repeated your first one. Maybe if you were in a cherry tree you wouldn't need the worst examples for propaganda purposes.
The first example was Uvalde, where police waited outside. The second example was Parkland, where a cop on campus left during the shooting, was sued for leaving and successfully defended in court his right to abandon the children he was hired to protect. The third is Lozito v NYC, in which police were sued for hiding from an attacker and, again, argued successfully in court that they have no duty to defend anyone from anything at any time. These all relate back to the original comment, that police aren't going to help in times of mass violence. Lozito and Parkland also undercut the argument that these were exceptions, mishandled incidents. In each case, the police actually went to court to establish a legal right to abandon citizens in times of danger. That's the difference between a one-off outlier and a systemic problem: instead of accountability, there has actually been institutional support for police that ignore their responsibilities.
Not necessarily. "Strawman" can also mean taking the most absurd example of something and propping it up as representative because it's easier to tear down.
GP is being downvoted because it's a hyperbolic strawman.