If your bar is at all competent they're using legal 1oz shot glasses, which means they're 1oz filled to the very top. Such glasses look like this:
The standardized shape allows bartenders to know exactly what measurements are in the glass so we don't have to freepour; 1/2 ounce is the same in all bars everywhere (speed spouts help too, but they're not as reliable). In BC, you aren't legally allowed to serve less than 1 oz of alcohol, so if someone short pours you ask for your ounce. That said, I don't know what the law is elsewhere.