He said "mass school shootings", you changed it to "school shootings". That could be the source of your dispute.
Bollocks it is. I'm disputing the use of the word 'rare'. More than zero in 8 months would count as far as I'm concerned, and there have been more than that, even if you want to restrict it to some definition of 'mass shooting' (there is no universally agreed one).
CNN says there have been 45 school shootings so far this year. https://www.cnn.com/us/school-shootings-fast-facts-dg/index.html
CBS says over 200. https://www.cbsnews.com/news/how-many-school-shootings-2024-apalachee-winder-georgia/ (These larger numbers are due to a broader definition of 'shooting' https://www.allsides.com/story/fact...-how-many-school-shootings-have-happened-2024 )
This wikipedia page lists 3 mass school shootings so far this year. Again, I say that is not rare by most countries' definition. https://en.wikipedia.org/wiki/List_of_mass_shootings_in_the_United_States_in_2024