The special prosecutor, Oppal and the perception of bias

OK, there are differences in the two cases.
But Terry Robertson is in trouble with the law society because he accepted an appointment as special prosecutor to look into allegations of irregularities and election law violations in Kash Heed's campaign without revealing his law firm had donated to the campaign. (Story here.)
By not disclosing the potential conflict, Robertson "failed to meet the expected standard that requires a lawyer to disclose to his client any previous connection to the parties in a matter," the society found.
The failure to disclose is the issue. But the underlying concern is that the government would have decided that Robertson could be seen to be biased and wouldn't have been appointed.
Which leads, again, to the appointment of Wally Oppal to head the inquiry into the Pickton investigation and the missing women investigation.
If a law firm donation to a candidate is seen to raise a potential conflict of interest, how can four years as a Liberal cabinet minister and public comments supporting the police investigation and questioning the need for an inquiry not raise the perception of bias?
(The Vancouver Sun backed Oppal's appointment in an editorial today. The fact that it took 560 words to come up with a lukewarm endorsement - how else to consider the phrase "Based on what we know, there is no reason to believe Oppal has an untenable conflict of interest because of his foray into partisan politics" - suggests the appointment remains questionable.)