Did i lose lp because my friend dodged?

Is that supposed to happen?I had 4 wins in a row and 80 lp then me and my friend started a game and he dodged because his game lagged.He lost 3 lp and we waited for the 5 min.After than we played a match which we won and i tought i was for series.After that we started another game and in the middle of it i realise i only have 90 lp?We won the game and i went to promos but why did i lose 10 lp for my friends dodge?