Tell the boss you have a sudden intense itch in your hands.
I don't see this as an option, it has None, Pattern, PIN, Password. I always use None on all my phones anyway, don't live in favelas to be afraid of phone being stolen.
It doesn't scare me... but then again, I'm not scared of jumping out of perfectly good airplanes.
And not all Walmarts are created equal. All I go to are quite nice. And I always mind my thing when shopping and breeze through Scan-n-go, no time to pay attention to "walmartians", if a rare species sample does happen to be around.