Nocturne mains sitting on a 28% AFK rate

So I was preening myself, looking at my ranked statistics online after a hard fought victory to extend my 4 game win streak. I soon found myself perusing the general NA statistics, and thereafter stumbled across a statistic that had me saying to myself "Holy sh*t, this cannot be real!"

Apparently, players who main Nocturne have a 28.69% afk rate in North America. By comparison, the second highest afk rate sits at a mere 8.93% (Heimerdinger mains), and the lowest sits at 2.66% (Elise mains).

Wtf is going on here?

The first logical conclusion is that Nocturne mains are hands down the most toxic players on the continent. However, as much as this tickles my funny bone, that doesn't ring true in my personal experience. It's the mid-laners and ADCs that tend to be feeding flamers. Therefore something unnatural has to be going on here which is causing the statistic to be skewed.

My second thought is bots. For those of you who are unaware, the league currently has a 'black market' where people can purchase fully leveled accounts online for real money. Individuals selling these acounts power-level them by setting up macro-programs to automate their champions through games so they don't get kicked by the leaver-buster and still get xp.

Is it possible that bot users are primarily using Nocturne to farm xp for some reason? If so, could these bots actually be inflating Noturne's loss rate? Could Nocturne actually be slightly overpowered, rather than slightly underpowered as his winrate suggests? The ramifications are fascinating.

Does anyone one have any other theories? This is a truly bizarre finding.

*It's worth mentioning that this is not a global thing. This applies specifically to NA. *And support mains are clustered at the bottom of the afk rate chart ;)