Just in favour of that point, there are significant changes between O'Brien and Bosc text and the former Marleau and Montpetit. In particular--this is very relevant--in the definitions of privilege in Marleau and Montpetit, there are only four privileges cited: freedom of speech; freedom from arrest in civil actions; exemption from jury duty, and thank goodness for that one; and exemption from being subpoenaed to attend court as a witness. But then O'Brien and Bosc add in freedom from obstruction, interference, intimidation, and molestation, which is the basis upon which Professor Cotler is making his assertion.
Their addition means they've presumably thought a great deal about this. They aren't simply passing on the wisdom of those who wrote before them, they're actually adding this in. Therefore, I think they would have a fair bit to say about the definition of these terms that might be helpful in an area where Mr. Walsh was unable to provide us with guidance, because we were going into parliamentary matters as opposed to legal matters.