Well what I found in the second time I went through a 5v5 match, I found that the icon for key "B" (your recall key) is bugged. Not the action itself, but the icon is smaller than the space that its set in. Not a big deal, but it must be fixed.
Second, I was running two screens. My regular iMac 27 inch and my Vizio 37 inch because I like to dual screen. Well I forgot to turn off my Vizio when I started the match and during the middle of the game, I turned my Vizio off. At the end of the match, this caused my pvp.net client to crash and I had to reboot League of Legends. Bug? Error? Glitch? I don't know, but its something to take a look into.
Other than that, nothing too big. I'll have more coverage over 5v5 and 3v3 soon.