The author could have done some research for a more intelligent article. The Texas statutes have something to say about "duty to protect" under Chapter 37 Subchapter C of the Texas Education Code:
(d-1) A school district peace officer, a school resource officer, and security personnel shall perform law enforcement duties for the school district that must include protecting:
(1) the safety and welfare of any person in the jurisdiction of the peace officer, resource officer, or security personnel; and
(2) the property of the school district.
Notice use of the word
shall. Since the stink has evidently fallen on the ISD police in this case they're gonna be in the hotseat. No escaping it.
The thing with that law (and many like it) is that the remedy for failure to adhere is usually absent. The words are there to make everybody feel good, nothing more.
The “no duty” theme is a reference to an ability to obtain money damages, sue the police for failure to perform a duty to protect, and that case will be thrown out of court. They can be sued for malfeasance but the hurdle there is extremely high. Deprivation of civil rights, excessive force, false arrest, that sort of malfeasance can result in civil and criminal penalties. But doing nothing results in, at worst, being fired from the job.