We were about 5 moves into the game and I got up to look at some games around me and when I came back I noticed that one of my center pawns was missing. I thought he must have captured it but quickly realized it was impossible. So then figured he had snatched and hid it somewhere, so I asked him

“did you take my pawn?” Before he answered though he made a weird sound almost like a gagging noice, like something was lodged in his throat. Then he was finally able to get out the word “No”. I was really confused but my rating was over 200 points higher than his so I thought whatever I’ll still win anyway. But unfortunately I went on to lose the match which pissed me off even more. Should I have contacted the arbiter in this situation? What should I have done?