@Frost it definitely happened because he reached level 150 while we hadn't implemented the new groups yet - so when we released this last Foundation update, he was put in the last only, skipping the previous ones. That's an unexpected behavior tho, he should have been added to all the groups in order.
It's not a critical bug since in the end I guess one always wants to display his highest title... but we'll have a look at it anyway, thanks for reporting.
...also, I just noticed he's now in all groups. Weird. We'll see!