What is the effect of a collective agreement that limited call-back premiums?

Had the Employer wished to insert into the Agreement the simple phrase that this premium would not be paid if the employee was called back to work for a time that was contiguous with the commencement of his or her next shift, it could have done so simply. Indeed, the 1983 decision of City of Toronto v. CUPE sets out such simple wording and, accordingly, it is reasonable to assume that these sophisticated parties were well aware of such wording in collective agreements. Similarly, other decisions referred to by the Majority that limited call-back premiums and applied the two trip theory did so in reliance on specific language in the specific contract provisions dealing with the call-back premium.