I feel sorry for Johnston, but he (and the PMO) really should've expected this mudslinging. Johnston was a fool to accept the position, and the PMO was foolish to offer it to him.
I have nothing but respect for David Johnston. I think he believed that it was his duty to serve Canadians when asked. That said - the PMO completely dropped the ball. By selecting someone without consulting the opposition leaders Trudeau guaranteed this outcome. The special raporteur - if that was the direction Trudeau wanted to go - had to be someone agreed upon with the opposition.
I wouldn't be remotely surprised if they did consult with the opposition leaders. Whether they did or they didn't though, neither party would've formed an opinion until after they saw how pundits and party faithful reacted; that's one of the benefits of being in the opposition.
So what now? Does Justin asking a new rapporteur or does he cave and we get the public inquiry? Feels like he has exhausted all his options and there's nothing else left.