If they want to do this right, they should have the polls close across the country at generally the same time. The way it's being done now clearly has loopholes that people can pick up on. The law was made with good intentions, but this isn't 20 years ago. It works in principle, but it cannot work in application in the internet age.
They do have the polls open and close at roughly the same time. There's a 4.5 hour gap between B.C. and Newfoundland, there's only so much you can do to keep things open evenly. So polls opened late in the morning in the Maritimes and closed lated, like at 8 or 8:30, while they opened at 7 in B.C. and close at 7 local time.
Simultaneous closings would mean either closing too early on the West Coast for people to go after work or keeping the polls open on the east coast until a ridiculously late hour.
They've moved in that direction starting with the 2004 election but with a 4 1/2 hour spread you can only do so much. Everything from Québec to Alberta closes at the same time with BC closing 30 minutes later.