21.— The matters to which the court in a defamation action shall have regard, for the purposes of distinguishing between a statement consisting of allegations of fact and a statement consisting of opinion, shall include the following:

(a) the extent to which the statement is capable of being proved;

(b) the extent to which the statement was made in circumstances in which it was likely to have been reasonably understood as a statement of opinion rather than a statement consisting of an allegation of fact; and

(c) the words used in the statement and the extent to which the statement was subject to a qualification or a disclaimer or was accompanied by cautionary words.