I think he was asking for his students to empathise with his needs based on his pre-existing health condition. He was asking them to make a reciprocal gesture

I think he was asking for his students to empathise with his needs based on his pre-existing health condition. He was asking them to make a reciprocal gesture of respect. Deliberately wearing a mask as to render it ineffective in the circumstance is deeply disrespectful. It’s a pity one student ruined it for the whole class, but upon reflection maybe a more important lesson will be learned by all.