There's been a great deal of attention over UBC law professor Benjamin Perrin's testimony today at the Mike Duffy trial.

Media outlets have zeroed in on his revelation that Stephen Harper's chief of staff, Ray Novak, was told in advance about a $90,000 payment to Duffy to cover expenses he had billed to the Senate.

The Conservatives have previously denied that Novak knew anything about the payment.

But what is perhaps more worrisome to Canadians is Perrin's testimony about Duffy's appointment as a senator from Prince Edward Island.

In 2012 and 2013, Perrin carried the lofty title of special adviser, legal affairs and policy in the Office of the Prime Minister.

Perrin testified that he was "taken aback" when Harper didn't follow through on his legal advice that Duffy wasn't legally qualified to represent Prince Edward Island in the Senate.

Duffy, a long-time Ottawa resident, was originally from the island but his Ontario residency disqualified him, in the eyes of Perrin. 

That didn't matter to Harper, though, who appointed the former broadcaster despite Perrin's concerns.

Perrin's biography on the Macdonald-Laurier Institute website describes his former role in Harper's office this way: "lead policy advisor on all matters related to the Department of Justice, Public Safety Canada (including the RCMP, Canada Border Services Agency, Canadian Security Intelligence Service, Correctional Service of Canada, and Parole Board of Canada), and Citizenship and Immigration Canada".

If Harper rejected Perrin's advice on Duffy's Senate appointment, it raises this question: on what other files did Harper pay no heed to his legal adviser's input? 

And is there any relationship between Harper's interaction with his legal advisers and his government's extensive losing streak in the Supreme Court of Canada?

These court cases cost litigants and the taxpayers vast sums of money through the appelate process. Here are some cases that Harper's government has taken to the top court and lost:

* Trying to shut down Vancouver's supervised injection site;

* Fighting two Ontario court rulings striking down prostitution-related laws;

* Opposing two B.C. court rulings related to medicinal cannabis.

* Battling to retain a federal ban on assisted suicide.

* Attempting to appoint a Federal Court of Canada judge based in Ontario to fill a Quebec seat on the Supreme Court of Canada.

Imagine the amount of money the government would have saved by not appointing Duffy to the Senate in the first place.

There would have been no lengthy RCMP investigation, no audit of his expenses, and no costly criminal trial related to his actions as a senator.

Harper likes to portray himself as some sort of guardian of the taxpayers' money. What a joke.