Wrong champion portrait in champ select

I've never seen this before now, but I did hear some other reports about it. I was playing an ARAM and in champ select it showed that I got Nami. I selected AP runes and masteries and allowed the game to begin. However, once the game started I was given Trundle, not Nami. Needless to say, I was even more useless than normal with the completely useless runes and masteries I had. Everybody in the game thought I was insane but this actually happened. I have no idea what splash art showed during the loading screen because I went afk once the game launched.

PS: I was not looking at the wrong player, either. Nobody in the game had Nami.