Me neither. I'd have fired him after Watford, however after the recovery and due to an overall decent December the timing is wrong now, but if he drops to a long distance from 4th again I'd have him out of the door faster than you can say Jack Robinson.
Tonnes of people could carry on this "project" and get better results doing it, that much we should all know because we've got tonnes of examples of how good managers can suddenly make the same squad perform miles better. You don't have to look any further than a guy in Leicester who took over a side in 12th last season and now has the exact same squad minus their best CB in 2nd place and looking superb.
The simple and smart thing to do next if Ole keeps dropping away is to target a few top managers and hire the one who likes the current project and can sell his version of it to you best. If any of them say "oh no, I need at least 2 years and 10 new players before my win rate can get anywhere near 50%", then he's not the man for us.
I would keep him for now, probably even till the end of the season as it becomes pointless to sack him the more we go deeper into the season, but he shouldn't safe in the job be by any means. We should start scouting other managers and talking with them so that when we decide to sack him in May we have the replacement ready.