I am curious to know if your opponent in that game passed because they wanted to score but are ignorant of the fact you need to enclose areas to count them as territory, or they know that and were just in a bad mood from getting killed a lot and being petulant. Given they are 14k if this was a rank anywhere other than OGS (e.g real-life or KGS) then I would assume the latter, as even 25ks know about closing territory to score, so 14ks definitely should, but I have seen numerous cases of people with ranks as high as 14k on OGS who somehow don’t know about this basic rule of scoring. My hypothesis is that learning online without a proper teacher, plus OGS’s terrible scoring system that doesn’t follow the rules of Go, contributes to this mass ignorance.