I'm not convinced it was nefarious. He might have just been trying to keep everything running while he saw if he could recuperate the losses.
I am inclined to think that. Earn enough interest on Coinlenders and use that to keep the bank operational and liquid. That's what all the other banks in the world do.
If someone breaks into a bank's vault, the bank might still survive as long as there are no massive simultaneous payout requests (bank run). If not for the current price hike, when a lot of people decided to cash out at the same time, inputs.io might have made it through the rough stretch and operational without anyone noticing any problems.
You are forgetting some detail there buddy, people noticed their bitcoins from inputs.io went missing. That is, they didn't even request a payout, they were taken from them. You are not going to see a real world bank doing that nowadays without facing huge problems (at least a country-wide kind of problem), please do not compare this to a bank in any way.