Obviously it's all speculation and hypothesis. I'm interested to hear their take on why the OPP would want to attach themselves to this case if it were a go-nowhere proposition, or a case with only minor charges facing Ford.
As far as has been reported, Blair was under no legal obligation to pass off the investigation of Ford, and it also hasn't been shown that the OPP was obligated to take the case on Blair's request. The decision to pass off oversight in a very public fashion seems to be based on political prerogatives.
I'm surmising that Blair's motivation was to shut down insinuations of bias and conspiracy. If he were doing so merely for the sake of his own reputation, I'm still at a loss to understand why the OPP would be so charitable as to expose themselves to the shit-storm that would result. What's the political advantage for the OPP, and the province at large, for attaching themselves to such a high profile failure?