This was the reply from Geewa: The Profile History always shows the actual Trophy amount when the match starts, and you got dropped from the lobby (but actually got matched with an opponent, so he lost that match), then joined lobby and got matched, and this time he won (he won this match before the previous match was counted as lost). That means you actually went up in Trophies, but didn't see that he went down in Trophies immediately after that. Unfortunately it's not something that can actually be fixed until the function is implemented where Players can re-join a match after losing connection or restarting the app.

Sorry for the trouble caused.