Florida has statutorily waived sovereign immunity to some extent via Fla. Stat. 768.28, so maybe. This article outlines the convoluted history of Florida case law surrounding public duty doctrine, noting that "Lower appellate courts are struggling to apply the incomprehensible law in this area", and notes that in most cases reaching them, the Supreme Court has not found a lack of government liability. Florida has not applied the public duty doctrine, and has specifically found a duty of care in a number of cases, typified by Kaisner v. Kolb, 543 So. 2d 732 (involving a traffic stop) where
petitioner was owed a duty of care by the police officers when he was
directed to stop and thus was deprived of his normal opportunity for
protection. Under our case law, our courts have found liability or
entertained suits after law enforcement officers took persons into
custody, otherwise detained them, deprived them of liberty or placed
them in danger
In the case of Wallace v. Dean, 3 So. 3d 1035, plaintiff's mother died after deputies responded to a 911 call and would not summon an ambulance to aid a woman in a diabetic coma. The Supreme Court observed that
the Sheriff's deputies did not attempt to enforce any law and
certainly were not engaged in the protection of the general public;
instead, they affirmatively sought to provide a service (a 911 safety
check) to a specific individual
The court reiterates their longstanding adherence to the doctrine that
[i]n every situation where a man undertakes to act, or to pursue a
particular course, he is under an implied legal obligation or duty to
act with reasonable care, to the end that the person or property of
others may not be injured by any force which he sets in operation, or
by any agent for which he is responsible. If he fails to exercise the
degree of caution which the law requires in a particular situation, he
is held liable for any damage that results to another
and particularly apt to the current question (as well as Wallace)
One who undertakes... to render services to another which he should
recognize as necessary for the protection of a third person ...is
subject to liability... if...the harm is suffered because of reliance
of the other or the third person upon the undertaking.
Since the officer in question is only described as a "school resource officer" and there has been no public release of a memorandum of understanding between the school district and the county sheriff, which would be material in determining whether there was a duty of care.