Combination of high wages paid and him running out of decent football clubs to manage. It's not overly common for clubs re-hire someone, but yeah, it was odd seeing him at Goodison. I'd love to have seen how quickly he packed his bags when the call from Real Madid came in. I strong suspect there's a Carlo shaped hole still in the office door at Finch Farm.
I reckon he kept a “Go Bag” close by at all times when he was managing Everton.