Please discuss the significance of the Supreme Court of Canada's decision in R. v. Barton by answering the following questions:

(1) How did the Court reframe the defence of "Mistaken belief in consent"?

(2) Is the defence available if it is a mistake of law?

(3) With respect to the issue of whether or not the accused took reasonable steps to ascertain that consent had been communicated, what three errors did the trial judge make?

(4) While the Court could not provide a list of what would constitute reasonable steps, it gave at least one example of what would NOT be reasonable steps. According to the Court, what would NOT be reasonable steps to ascertain that consent had been communicated?