I appreciate the concerns you're voicing. I would imagine that any time a reverse onus comes up in any part of criminal procedure, there is a similar kind of concern that arises in the sense that an onus that's cast upon the affected party obliges them to answer in some way. Answering directly by testifying is something that perhaps one can see as a violation of a right to silence. I don't believe that in reverse onus cases when a person is called upon to answer, it is necessarily characterized that way in the jurisprudence, but from, let's say, a psychological or a tactical point of view, I understand the point you are getting at.
I would say this about the right to silence. The right to silence is not expressly mentioned in the Constitution. It has emerged in the case law under section 7. I know that you have been referred to the Hebert case in relation to section 7 and its relation to the right to silence. More recently, just two or three weeks ago, the Supreme Court, in a case called Singh, which dealt with the case of repeated police questioning while an individual was in custody, ruled in an expansive way, suggesting that the right to silence did not prevent the police from repeatedly questioning an individual in the face of new evidence and new circumstances that called for questions that required an answer.
I see the chair is looking at me as though I'm answering too hard.