Mistake of fact and due diligence are different defences

R. v. Legrande 2013 ABCA 229 makes clear the distinction between mistake of fact and due diligence. 

For strict liability offences a reasonable belief in a mistaken set of facts that would render the act innocent is a defence.  Due diligence, that is taking all reasonable sets to avoid the wrongful act, is also a defence.

But they are different defences and combining the two in some "reasonableness" standard is an error of law.