Generally not. The rule requires a year of qualifying employment with the organization, and services invoiced through the individual's own corporation are ordinarily a commercial relationship rather than employment. The employment records, not the length of association, determine when the qualifying year began.
Pull the payroll and count from the real start
Ask the bookkeeper for the date the individual was first placed on payroll, the source deduction records, and the employment agreement if one exists. That is the date to count from. Where the earlier period was in substance employment despite the invoicing arrangement, the argument is possible but it needs evidence: direction and control by the company, set hours, integration into the organization, and an explanation of why the parties structured it as they did. That is a harder case to make than simply waiting until the twelve months of unambiguous employment are complete, and in most situations the patient route is the better one. Meanwhile, check whether an earlier period with the same group, anywhere in the preceding three years, already satisfies the requirement.
Hypothetical example: a Tyendinaga maker of stage equipment calls its production lead a director, yet she personally schedules every shift and installs equipment. The first review tests duties rather than titles, using organization charts, payroll, job descriptions, and examples of decisions she makes through others. If the record shows day-to-day production instead of managerial direction, the company may need to change the assignment or use a different staffing plan. That evidence should describe authority over people, budget, or a defined function in concrete terms rather than relying on executive-sounding labels.