Some pepper sprays are rated at 2 million SHU which is hotter than any pepper on the market. The inmate was already tied to a chair any further force was not justified.
No pepper spray is as hot as the chile I eat. I knew a self-defense instructor/gun shop owner/former cop who took his best pepper spray to his classes along with a burrito. He started his classes by spraying down his burrito with the pepper spray and eating it. It’s tame compared to good chile.