As far as writing up employees for not clocking out at exactly the end of their shift and getting a few minutes overtime, I’m sure Wal-mart or somebody lost a big case to the labour board and it cost the company big bucks.
The availability of overtime hours is not a right. And many if not most companies, retails and other employers like manufacturers, have rules regarding clocking out in a timely fashion at the end of your shift. Most time clocks have a rounding mechanism, usually anywhere from 5 to 10 minutes on either side of a shift punch. Where I work, we allow for overtime if it is approved by the shift manager. If an employee is constantly punching out late without a legitimate reason for punching out late, they will be written up and terminated if it continues.
Up here in Canada, Safeway, has an agreement with the union that whomever works 13 straight weeks of 40 hours a week, has to be bumped up to full-time on a permanent basis.
So, anybody who has gone 12 weeks at 40 hours/week, they get red flagged by the computer, so Safeway can knock their hours down that week so they don’t qualify.