Not that I'm complaining...

I bought Maokai this morning before logging off. I noticed the IP wasn't immediately deducted, but I still had the champion. I just logged on to notice I still have 16K IP. I know I wasn't charged because I've been watching it to make sure I'll have enough once Aurelion Sol is released. I would have noticed if I had 20K IP at any point, Mao is a 4800 champ.

I'm not sure if this is a bug regarding buying champs, or if it has something to do with Hextech considering I bought him after unlocking the 'dead tree' ward skin.