He's more worried about MCs health IIRC. Cuz in the novel, he spent a lot of energy doing first aid to the guy who collapsed. Yeonsoo gets hospitalized after this too cuz it really drained his energy (like empty empty).
Also let's remember that Yeonsoo is an unreliable narrator because he assumes that ML is still the same from the book. (He's defo still obsessed but less extreme)

Novel readers im needy, what happened afterwards?! Like is ml gonna go on a jealous stint for saving tht mans life?