[Client] Post-game screen is a mix of my game and somebody else's

Here's the sequence of what happened. A few screenshots are here http://imgur.com/a/5ZIrK

• A friend of mine was spectating his brother's game earlier
• Before I started my last game, I tried to drop into the game he was spectating, to see what he was watching, but no game would launch (Guessing he had to AFK so he's just sitting on the victory screen of that game, but it's no longer active)
• I queued up for an ARAM, played the game, and went 21/7/16 with Xerath (record is relevant to note here)
• Post game screen comes up, and I was really curious to see what grade that would be for Xer on ARAM, but the grade never loads. Only the blue circle around the grade spinning around and around
• I then noticed that the names/champs in the upper right box were all wrong. I'm guessing it was the players from the game I had attempted to spectate when it was already over (my friend's brother is one of them). That game was on SR, not even an ARAM
• Looked at the Grid and Graph tabs, and all the stats displayed are from the other game, not mine

Now, I did look back in my champions list, and it appears the grade and points still were applied for Xerath. I don't think I had any mastery points on him prior to this game, and now he's showing level 1 with a season-high A+.